题目：https://pintia.cn/problem-sets/994805342720868352/problems/994805386161274880

这题注意一下各个函数的，处理，尤其是约分那部分，涉及的函数很多。

  1. 结构体
  2. 最大公约数gcd
  3. 约分函数
  4. 加法函数
  5. 显示函数

代码

  1. typedef long long ll;
  1. #include<algorithm>
  2. #include<iostream>
  3. #include<vector>
  4. using namespace std;
  6. struct Fraction{
  7.     long long up, down;
  8. };
  10. long long gcd(long long a, long long b){
  11.     if( b == 0 )return a;
  12.     else return gcd(b, a % b);
  13. }
  15. Fraction reduction(Fraction a){
  16.     if(a.down < 0) {
  17.         a.up *= -1;
  18.         a.down *= -1;
  19.     }
  20.     if(a.up == 0){
  21.         a.down = 1;
  22.     } else {
  23.         int d = gcd(a.up, a.down);
  24.         a.up /= d;
  25.         a.down /= d;
  26.     }
  27.     return a;
  28. }
  30. Fraction add(Fraction a, Fraction b){
  31.     Fraction temp;
  32.     temp.up = a.up * b.down + a.down * b.up;
  33.     temp.down = a.down * b.down;
  34.     return reduction(temp);
  35. }
  37. void show_Fra(Fraction a){
  38.     reduction(a);
  39.     if(a.down == 1) printf("%lld",a.up);
  40.     else if(abs(a.up) > a.down) printf("%lld %lld/%lld",a.up / a.down, a.up - a.down * (a.up / a.down), a.down);
  41.     else printf("%lld/%lld",a.up, a.down);
  42. }
  44. int main(){
  45.     int n;
  46.     scanf("%d",&n);
  47.     vector<Fraction> Fra_list(n);
  48.     for(int i = 0; i < n; i++){
  49.         scanf("%lld/%lld", &Fra_list[i].up, &Fra_list[i].down);
  50.     }
  51.     Fraction result;
  52.     result.up = 0, result.down = 1;
  53.     for(int i = 0; i < n; i++){
  54.         result = add(result, Fra_list[i]);
  55.     }
  56.     show_Fra(result);
  57.     return 0;
  58. }