POJ1611

来源：互联网发布：2017pta编程题答案编辑：程序博客网时间：2024/04/26 05:54

计算被感染人的数量，开一个数组记录数量，水题。

#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int N = 30005;int f[N], num[N], arr[N];int n, m;void init() {    for (int i = 0; i < n; i++) {        f[i] = i;        num[i] = 1;    }}int find(int x) {    return x == f[x] ? x : f[x] = find(f[x]);}void Union(int a, int b) {    int pa = find(a);    int pb = find(b);    if (pa != pb) {        if (num[pa] >= num[pb]) {            f[pb] = pa;            num[pa] += num[pb];        }        else {            f[pa] = pb;            num[pb] += num[pa];        }    }}int main() {    while (scanf("%d %d", &n, &m) && (n || m)) {        int k;        init();        while (m--) {            scanf("%d", &k);            for (int i = 0; i < k; i++)                  scanf("%d", &arr[i]);            for (int i = 1; i < k; i++)                Union(arr[0], arr[i]);        }        int p = find(0);        printf("%d\n", num[p]);    }    return 0;}

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