#include <bits/stdc++.h> using namespace std; map<int, int> f; int find(int a) { if (f[a] != a) return f[a] = find(f[a]); else return a; } int hb(int a, int b) { f[find(b)] = find(a); } int main() { int n, m, p, q; cin >> n >> m >> p >> q; for (int i = -m; i <= n; i++) { if (i == 0) continue; f[i] = i; } f[-1] = f[1]; int x, y; while (p--) { cin >> x >> y; hb(x, y); } while (q--) { cin >> x >> y; hb(x, y); } int girl = 0, boy = 0; for (int i = -m; i < 0; i++) { if (find(i) == 1) girl++; } for (int i = 1; i <= n; i++) { if (find(i) == 1) boy++; } cout << min(boy, girl); return 0; }换成c语言

这是将C++代码转换为C语言代码的结果：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAXN 100010

int f[MAXN];

int find(int a) {
    if (f[a] != a)
        return f[a] = find(f[a]);
    else
        return a;
}

void hb(int a, int b) {
    f[find(b)] = find(a);
}

int main() {
    int n, m, p, q;
    scanf("%d %d %d %d", &n, &m, &p, &q);

    for (int i = -m; i <= n; i++) {
        if (i == 0) continue;
        f[i] = i;
    }

    f[-1] = f[1];

    int x, y;

    while (p--) {
        scanf("%d %d", &x, &y);
        hb(x, y);
    }

    while (q--) {
        scanf("%d %d", &x, &y);
        hb(x, y);
    }

    int girl = 0, boy = 0;

    for (int i = -m; i < 0; i++) {
        if (find(i) == 1) girl++;
    }

    for (int i = 1; i <= n; i++) {
        if (find(i) == 1) boy++;
    }

    printf("%d", boy < girl ? boy : girl);

    return 0;
}

主要的改动包括：

- 使用头文件`<stdio.h>`和`<stdlib.h>`代替`<bits/stdc++.h>`；
- 将`cin`和`cout`改成`scanf`和`printf`；
- 将`map`改成一维数组`f`；
- 去掉`using namespace std`；
- 修改`int hb(int a, int b)`函数为`void hb(int a, int b)`函数；
- 修改`min(boy, girl)`为`boy < girl ? boy : girl`。