P5718 【深基4.例2】找最小值

  1. import java.util.ArrayList;
  2. import java.util.Comparator;
  3. import java.util.Scanner;
  5. public class Main {
  6.     public static void main(String[] args) {
  7.         Scanner sc = new Scanner(System.in);
  8.         int n = sc.nextInt();
  9.         ArrayList<Integer> list = new ArrayList<>(n);
  10.         for (int i = 0; i < n; i++) {
  11.             list.add(sc.nextInt());
  12.         }
  13.         list.sort(Comparator.naturalOrder());
  14.         System.out.println(list.get(0));
  15.     }
  16. }

P5719 【深基4.例3】分类平均

  1. import java.util.ArrayList;
  2. import java.util.Scanner;
  4. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         double n = sc.nextDouble();
  8.         double k = sc.nextInt();
  9.         ArrayList<Double> listYes = new ArrayList<>();
  10.         ArrayList<Double> listNo = new ArrayList<>();
  11.         for (double i = 1; i <= n; i++) {
  12.             if(i/k!=0 && i%k==0){
  13.                 listYes.add(i);
  14.             }else {
  15.                 listNo.add(i);
  16.             }
  17.         }
  18.         double sum1 = 0;
  19.         double sum2 = 0;
  20.         for(double i : listYes){
  21.             sum1 += i;
  22.         }
  23.         for(double j : listNo){
  24.             sum2 += j;
  25.         }
  26.         System.out.printf("%.1f %.1f",sum1/listYes.size(),sum2/listNo.size());
  27.     }
  28. }

P5720 【深基4.例4】一尺之棰

  1. import java.util.Scanner;
  3. public class Main {
  4.     public static void main(String[] args) {
  5.         Scanner sc = new Scanner(System.in);
  6.         int len = sc.nextInt();
  7.         int count = 1;
  8.         while(len!=1){
  9.             len /= 2;
  10.             count++;
  11.         }
  12.         System.out.println(count);
  13.     }
  14. }

P5721 【深基4.例6】数字直角三角形

  1. import java.util.Scanner;
  3. public class Main {
  4.     public static void main(String[] args) {
  5.         Scanner sc = new Scanner(System.in);
  6.         int n = sc.nextInt();
  7.         int count = 1;
  8.         for (int i = 0; i < n; i++) {
  9.             for (int j = 0; j < n-i; j++) {
  10.                 if(count < 10){
  11.                     System.out.print(0 +""+ count);
  12.                 }else {
  13.                     System.out.print(count);
  14.                 }
  15.                 count++;
  16.             }
  17.             System.out.println();
  18.         }
  19.     }
  20. }

P1009 [NOIP1998 普及组] 阶乘之和

  1. import java.math.BigInteger;
  2. import java.util.Scanner;
  4. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         int n = sc.nextInt();
  8.         BigInteger sum = new BigInteger("0");
  9.         for (int i = 1; i <= n; i++) {
  10.             sum = sum.add(factorial(i));
  11.         }
  12.         System.out.println(sum);
  13.     }
  15.     public static BigInteger factorial(int n){
  16.         BigInteger sum = new BigInteger("1");
  17.         for (int i = 1; i <= n; i++) {
  18.             sum = sum.multiply(new BigInteger(Integer.toString(i)));
  19.         }
  20.         return sum;
  21.     }
  22. }

P1980 [NOIP2013 普及组] 计数问题

  1. import java.util.Scanner;
  3. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         int n = sc.nextInt();
  8.         int x = sc.nextInt();
  9.         int sum = 0;
  10.         for (int i = 1; i <= n; i++) {
  11.             sum += check(i,x);
  12.         }
  13.         System.out.println(sum);
  14.     }
  16.     public static int check(int i,int x){
  17.         int sum = 0;
  18.         while(i!=0){
  19.             if(i%10 == x){
  20.                 sum++;
  21.             }
  22.             i /= 10;
  23.         }
  24.         return sum;
  25.     }
  26. }

P1035 [NOIP2002 普及组] 级数求和

  1. import java.util.Scanner;
  3. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         double k = sc.nextDouble();
  8.         double sum = 0;
  9.         double n = 1;
  10.         while(sum <= k){
  11.             sum+=1/n;
  12.             n++;
  13.         }
  14.         System.out.print((int) n-1);
  15.     }
  17. }

P2669 [NOIP2015 普及组] 金币

  1. import java.util.Scanner;
  3. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         int k = sc.nextInt();
  8.         int sum = 0;
  9.         int days = 0;
  10.         for (int i = 1; i <= k; i++) {
  11.             for (int j = 1; j <= i; j++) {
  12.                 sum += i;
  13.                 days++;
  14.                 if(days == k){
  15.                     System.out.println(sum);
  16.                     return;
  17.                 }
  18.             }
  19.         }
  21.     }
  22. }

P5722 【深基4.例11】数列求和

  1. import java.util.Scanner;
  3. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         int n = sc.nextInt();
  8.         int sum = 0;
  9.         for (int i = 1; i <= n; i++) {
  10.             sum += i;
  11.         }
  12.         System.out.println(sum);
  13.     }
  14. }

P5723 【深基4.例13】质数口袋

  1. import java.util.ArrayList;
  2. import java.util.Scanner;
  4. public class Main {
  5.     public static void main(String[] args) {
  6.         Scanner sc = new Scanner(System.in);
  7.         ArrayList<Integer> list = new ArrayList<>();
  8.         int L = sc.nextInt();
  9.         int sum = 0;
  10.         for (int i = 2;; i++) {
  11.             if(sum+i>L){
  12.                 break;
  13.             }
  14.             if(isPrime(i)){
  15.                 list.add(i);
  16.                 sum += i;
  17.             }
  18.         }
  19.         for (Integer integer : list) {
  20.             System.out.println(integer);
  21.         }
  22.         System.out.println(list.size());
  23.     }
  25.     public static boolean isPrime(int n){
  26.         for (int i = 2; i < n; i++) {
  27.             if(n%i==0){
  28.                 return false;
  29.             }
  30.         }
  31.         return true;
  32.     }
  33. }

P1217 [USACO1.5]回文质数 Prime Palindromes

  1. import java.util.Scanner;
  3. public class Main {
  4.     public static void main(String[] args) {
  5.         Scanner sc = new Scanner(System.in);
  6.         int a = sc.nextInt();
  7.         int b = sc.nextInt();
  8.         int[] arr={5,7,11,101,131,151,181,191,313,353,373,383,727,757,787,797,919,929,10301,10501,10601,11311,11411,12421,12721,12821,13331,13831,13931,14341,14741,15451,15551,16061,16361,16561,16661,17471,17971,18181,18481,19391,19891,19991,30103,30203,30403,30703,30803,31013,31513,32323,32423,33533,34543,34843,35053,35153,35353,35753,36263,36563,37273,37573,38083,38183,38783,39293,70207,70507,70607,71317,71917,72227,72727,73037,73237,73637,74047,74747,75557,76367,76667,77377,77477,77977,78487,78787,78887,79397,79697,79997,90709,91019,93139,93239,93739,94049,94349,94649,94849,94949,95959,96269,96469,96769,97379,97579,97879,98389,98689,1003001,1008001,1022201,1028201,1035301,1043401,1055501,1062601,1065601,1074701,1082801,1085801,1092901,1093901,1114111,1117111,1120211,1123211,1126211,1129211,1134311,1145411,1150511,1153511,1160611,1163611,1175711,1177711,1178711,1180811,1183811,1186811,1190911,1193911,1196911,1201021,1208021,1212121,1215121,1218121,1221221,1235321,1242421,1243421,1245421,1250521,1253521,1257521,1262621,1268621,1273721,1276721,1278721,1280821,1281821,1286821,1287821,1300031,1303031,1311131,1317131,1327231,1328231,1333331,1335331,1338331,1343431,1360631,1362631,1363631,1371731,1374731,1390931,1407041,1409041,1411141,1412141,1422241,1437341,1444441,1447441,1452541,1456541,1461641,1463641,1464641,1469641,1486841,1489841,1490941,1496941,1508051,1513151,1520251,1532351,1535351,1542451,1548451,1550551,1551551,1556551,1557551,1565651,1572751,1579751,1580851,1583851,1589851,1594951,1597951,1598951,1600061,1609061,1611161,1616161,1628261,1630361,1633361,1640461,1643461,1646461,1654561,1657561,1658561,1660661,1670761,1684861,1685861,1688861,1695961,1703071,1707071,1712171,1714171,1730371,1734371,1737371,1748471,1755571,1761671,1764671,1777771,1793971,1802081,1805081,1820281,1823281,1824281,1826281,1829281,1831381,1832381,1842481,1851581,1853581,1856581,1865681,1876781,1878781,1879781,1880881,1881881,1883881,1884881,1895981,1903091,1908091,1909091,1917191,1924291,1930391,1936391,1941491,1951591,1952591,1957591,1958591,1963691,1968691,1969691,1970791,1976791,1981891,1982891,1984891,1987891,1988891,1993991,1995991,1998991,3001003,3002003,3007003,3016103,3026203,3064603,3065603,3072703,3073703,3075703,3083803,3089803,3091903,3095903,3103013,3106013,3127213,3135313,3140413,3155513,3158513,3160613,3166613,3181813,3187813,3193913,3196913,3198913,3211123,3212123,3218123,3222223,3223223,3228223,3233323,3236323,3241423,3245423,3252523,3256523,3258523,3260623,3267623,3272723,3283823,3285823,3286823,3288823,3291923,3293923,3304033,3305033,3307033,3310133,3315133,3319133,3321233,3329233,3331333,3337333,3343433,3353533,3362633,3364633,3365633,3368633,3380833,3391933,3392933,3400043,3411143,3417143,3424243,3425243,3427243,3439343,3441443,3443443,3444443,3447443,3449443,3452543,3460643,3466643,3470743,3479743,3485843,3487843,3503053,3515153,3517153,3528253,3541453,3553553,3558553,3563653,3569653,3586853,3589853,3590953,3591953,3594953,3601063,3607063,3618163,3621263,3627263,3635363,3643463,3646463,3670763,3673763,3680863,3689863,3698963,3708073,3709073,3716173,3717173,3721273,3722273,3728273,3732373,3743473,3746473,3762673,3763673,3765673,3768673,3769673,3773773,3774773,3781873,3784873,3792973,3793973,3799973,3804083,3806083,3812183,3814183,3826283,3829283,3836383,3842483,3853583,3858583,3863683,3864683,3867683,3869683,3871783,3878783,3893983,3899983,3913193,3916193,3918193,3924293,3927293,3931393,3938393,3942493,3946493,3948493,3964693,3970793,3983893,3991993,3994993,3997993,3998993,7014107,7035307,7036307,7041407,7046407,7057507,7065607,7069607,7073707,7079707,7082807,7084807,7087807,7093907,7096907,7100017,7114117,7115117,7118117,7129217,7134317,7136317,7141417,7145417,7155517,7156517,7158517,7159517,7177717,7190917,7194917,7215127,7226227,7246427,7249427,7250527,7256527,7257527,7261627,7267627,7276727,7278727,7291927,7300037,7302037,7310137,7314137,7324237,7327237,7347437,7352537,7354537,7362637,7365637,7381837,7388837,7392937,7401047,7403047,7409047,7415147,7434347,7436347,7439347,7452547,7461647,7466647,7472747,7475747,7485847,7486847,7489847,7493947,7507057,7508057,7518157,7519157,7521257,7527257,7540457,7562657,7564657,7576757,7586857,7592957,7594957,7600067,7611167,7619167,7622267,7630367,7632367,7644467,7654567,7662667,7665667,7666667,7668667,7669667,7674767,7681867,7690967,7693967,7696967,7715177,7718177,7722277,7729277,7733377,7742477,7747477,7750577,7758577,7764677,7772777,7774777,7778777,7782877,7783877,7791977,7794977,7807087,7819187,7820287,7821287,7831387,7832387,7838387,7843487,7850587,7856587,7865687,7867687,7868687,7873787,7884887,7891987,7897987,7913197,7916197,7930397,7933397,7935397,7938397,7941497,7943497,7949497,7957597,7958597,7960697,7977797,7984897,7985897,7987897,7996997,9002009,9015109,9024209,9037309,9042409,9043409,9045409,9046409,9049409,9067609,9073709,9076709,9078709,9091909,9095909,9103019,9109019,9110119,9127219,9128219,9136319,9149419,9169619,9173719,9174719,9179719,9185819,9196919,9199919,9200029,9209029,9212129,9217129,9222229,9223229,9230329,9231329,9255529,9269629,9271729,9277729,9280829,9286829,9289829,9318139,9320239,9324239,9329239,9332339,9338339,9351539,9357539,9375739,9384839,9397939,9400049,9414149,9419149,9433349,9439349,9440449,9446449,9451549,9470749,9477749,9492949,9493949,9495949,9504059,9514159,9526259,9529259,9547459,9556559,9558559,9561659,9577759,9583859,9585859,9586859,9601069,9602069,9604069,9610169,9620269,9624269,9626269,9632369,9634369,9645469,9650569,9657569,9670769,9686869,9700079,9709079,9711179,9714179,9724279,9727279,9732379,9733379,9743479,9749479,9752579,9754579,9758579,9762679,9770779,9776779,9779779,9781879,9782879,9787879,9788879,9795979,9801089,9807089,9809089,9817189,9818189,9820289,9822289,9836389,9837389,9845489,9852589,9871789,9888889,9889889,9896989,9902099,9907099,9908099,9916199,9918199,9919199,9921299,9923299,9926299,9927299,9931399,9932399,9935399,9938399,9957599,9965699,9978799,9980899,9981899,9989899};
  9.         int i = 0;
  10.         while(i<779){
  11.             if(arr[i]>=a && arr[i]<=b){
  12.                 System.out.println(arr[i]);
  13.             }
  14.             i++;
  15.         }
  16.     }
  17. }

P1423 小玉在游泳

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double x = sc.nextDouble();
        double speed = 2;
        double sum = 0;
        int count = 0;
        while(sum < x){
            sum += speed;
            speed *= 0.98;
            count++;
        }
        System.out.println(count);
    }
}

P1307 [NOIP2011 普及组] 数字反转

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        if(n==0){
            System.out.println(0);
            return;
        }
        while(n%10 == 0){
            n /= 10;
        }
        StringBuffer sb = new StringBuffer(n+"");
        if (n<0){
            sb.deleteCharAt(0);
            sb.append("-");
        }
        System.out.print(sb.reverse());
    }
}

P1720 月落乌啼算钱（斐波那契数列）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double n = sc.nextDouble();
        double result = (Math.pow((1+Math.sqrt(5))/2,n) - Math.pow((1-Math.sqrt(5))/2,n))/Math.sqrt(5);
        System.out.printf("%.2f",result);
    }
}

P5724 【深基4.习5】求极差 / 最大跨度值

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        ArrayList<Integer> list = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            list.add(sc.nextInt());
        }
        list.sort(Comparator.naturalOrder());
        System.out.println(list.get(n-1) - list.get(0));
    }
}

P1420 最长连号

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for (int i = 0; i < n; i++) {
            list[i] = sc.nextInt();
        }
        //最短是一个,不是0个
        int count = 1;
        int maxCount = 1;
        for (int i = 0; i < list.length-1; i++) {
            if(list[i+1]-list[i] == 1){
                count++;
            }else {
                //断开了就开始重新数
                count = 1;
            }
            //每次都检验一下,更新maxCount
            if (count > maxCount){
                maxCount = count;
            }
        }
        System.out.println(maxCount);
    }
}

P1075 [NOIP2012 普及组] 质因数分解

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int max = 2;
        for (int i = 2; i <= n/2; i++) {
            if(n%i == 0){
                System.out.println(n/i);
                return;
            }
        }
    }
}

P5725 【深基4.习8】求三角形

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        //打印正方形
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n ; j++) {
                int num = (i-1)*n + j;
                if(num<10){
                    System.out.print("0"+num);
                }else {
                    System.out.print(num);
                }
            }
            System.out.println();
        }
        //换行
        System.out.println();
        //打印三角
        int count = 1;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                //第i行就打印i个数字,剩余n-i都是空格
                if(j<=n-i){
                    System.out.print("  ");
                }else {
                    if(count<10){
                        System.out.print("0");
                    }
                    System.out.print(count);
                    count++;
                }
            }
            System.out.println();
        }
    }
}

P5726 【深基4.习9】打分

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<Double> list = new ArrayList<>();
        double n = sc.nextInt();
        double sum = 0;
        for (int i = 0; i < n; i++) {
            list.add(sc.nextDouble());
        }
        list.sort(Comparator.naturalOrder());
        list.remove(0);
        list.remove(list.size()-1);
        for(Double i : list){
            sum += i;
        }
        System.out.printf("%.2f",sum/(n-2));
    }
}

P4956 [COCI2017-2018#6] Davor

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = 1;
        while(true){
            for (int x = 100; x >= 1; x--) {
                if(52*(7*x+21*k) == n){
                    System.out.println(x);
                    System.out.println(k);
                    return;
                }
            }
            k++;
        }
    }
}

P1089 [NOIP2004 提高组] 津津的储蓄计划

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sum = 0;
        int storage = 0;
        for (int i = 0; i < 12; i++) {
            //月初发300
            sum += 300;
            //扣除花费
            sum = sum - sc.nextInt();
            if(sum<0){
                System.out.println("-" + (i+1));
                return;
            }
            if(sum>=100){
                //存入整百
                storage += sum/100;
                sum -= (sum/100)*100;
            }
        }
        System.out.println(sum + storage*120);
    }
}