对拍，分为《自动对拍》和《手动对拍》，基础材料都是暴利解和尝试的正解程序，造数据这块，可以系统自动生成，也可以手动人为构造数据。

对拍，在提高组高分阶段是有用的，在普及组阶段，使用甚少。

参考：https://www.cnblogs.com/EdisonBa/p/13509379.html

新版

例题，Trailing Zeroes (III) LightOJ - 1138

// duipai.cpp
#include <bits/stdc++.h>
//#include <unistd.h>
using namespace std;
int main(){
    int T = 50;
    system("g++ -o gen gen.cpp");
    system("g++ -o baoli baoli.cpp");
    system("g++ -o std A.cpp");
    for (int i = 1; i <= T; i++){
        system("./gen > data.in");
        system("./baoli < data.in > baoli.out");
        system("./std < data.in > std.out");
        if (system("diff baoli.out std.out")){
            printf("WA on test %d\n", i);
            return 0;
        }
        else{
            printf("AC on test %d\n", i);
        }
        //sleep(1);
        //usleep(500);
    }
    return 0;
}

// gen.cpp
#include <bits/stdc++.h>
using namespace std;
int rnd(int l, int r){
    return l + rand() % (r - l + 1);
}
int main(){
    //freopen("data.in", "w", stdout);
    srand((int)time(0));
    int T = rnd(1, 5);
    printf("%d\n", T);
    while (T--){
        printf("%d\n", rnd(1, 1e2));
    }
    return 0;
}

// baoli.cpp
#include <bits/stdc++.h>
using namespace std;
int T, q;
int check(int x){
    int t = 0;
    while (x){
        t += x / 5;
        x /= 5;
    }
    return t;
}
int main(){
    //freopen("data.in", "r", stdin);
    //freopen("baoli.out", "w", stdout);
    //cout << check(1e9) << '\n';
    cin >> T;
    for (int i = 1; i <= T; i++){
        cin >> q;
        int j;
        for (j = 1; j <= 1e5; j++){
            if (check(j) == q) break;
        }
        if (check(j) == q) printf("Case %d: %d\n", i, j);
        else printf("Case %d: impossible\n", i);
    }
    return 0;
}

// A.cpp
#include <bits/stdc++.h>
using namespace std;
int T, q;
int check(int x){
    int t = 0;
    while (x){
        t += x / 5;
        x /= 5;
    }
    return t;
}
int main(){
    //freopen("data.in", "r", stdin);
    //freopen("std.out", "w", stdout);
    //cout << check(1e9) << '\n';
    cin >> T;
    for (int i = 1; i <= T; i++){
        cin >> q;
        int l = 0, r = 1e9, best = -1;
        while (l <= r){
            int mid = (l + r) >> 1;
            if (check(mid) >= q){
                best = mid;
                r = mid - 1;
            }
            else{
                l = mid + 1;
            }
        }
        if (check(best) == q) printf("Case %d: %d\n", i, best);
        else printf("Case %d: impossible\n", i);
    }
    return 0;
}

旧版

生成数据

// gen.cpp
#include <bits/stdc++.h>
using namespace std;
int rnd(int l, int r){
    return l + rand() % (r - l + 1);
}
int main(){
    freopen("data.in", "w", stdout);
    srand((int)time(0));
    printf("%d %d\n", rnd(30, 50), rnd(70, 90));
    return 0;
}

暴力程序和优化程序

// A.cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
    freopen("data.in", "r", stdin);
    freopen("A.out", "w", stdout);
    int a, b;
    cin >> a >> b;
    cout << a + b << '\n';
    return 0;
}
// B.cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
    freopen("data.in", "r", stdin);
    freopen("B.out", "w", stdout);
    int a, b;
    cin >> a >> b;
    cout << a - b << '\n';
    return 0;
}

对拍程序

// duipai.cpp
// linux下演示, diff命令
// Windows下，是fc命令 system("fc A.out B.out");
// cmd终端暂停查看，system("pause");
#include <bits/stdc++.h>
using namespace std;
int main(){
    int T = 10;
    for (int i = 1; i <= T; i++){
        system("./gen");
        system("./A");
        system("./B");
        if (system("diff A.out B.out")){
            printf("WA on test%d\n", i);
            return 0;
        }
        else{
            printf("AC on test%d\n", i);
        }
    }
    return 0;
}