ZOJ 3261 Connections in Galaxy War

#include <cstdio>
#include <map>
using namespace std;

#define N 10001
#define NN 50001
#define swap(x,y) x=x^y;y=x^y;x=x^y;

struct Node {
    int a, b;
    bool m;  //两种指令
} edge[N << 1], que[NN];  //边,指令
int fa[N], pw[N], ans[NN];  //父节点,power值,答案
map<int, bool> mp;  //标记被破坏的边

void init(int n) {
    mp.clear();
    for (int i = 0; i < n; i++) {
        fa[i] = i;
    }
}

int findfa(int n) {
    return n == fa[n] ? n : fa[n] = findfa(fa[n]);
}

void unite(int a, int b) {
    a = findfa(a);
    b = findfa(b);
    if (a != b) {
        if (pw[a] > pw[b] || pw[a] == pw[b] && a < b) {  //power大及编号小的为父节点
            fa[b] = a;
        }
        else {
            fa[a] = b;
        }
    }
}

int main() {
    int n, m, q;
    char c[8];
    bool f = 1;
    while (~scanf("%d", &n)) {
        if (!f) {
            printf("\n");
        }
        f = 0;
        init(n);
        for (int i = 0; i < n; i++) {
            scanf("%d", &pw[i]);
        }
        scanf("%d", &m);
        for (int i = 0; i < m; i++) {
            scanf("%d%d" , &edge[i].a , &edge[i].b);
            if (edge[i].a > edge[i].b) {
                swap(edge[i].a , edge[i].b);  //小号在前
            }
        }
        scanf("%d", &q);
        for (int i = 0; i < q; i++) {
            scanf("%s", c);
            if (c[0] == ‘d‘) {
                scanf("%d%d", &que[i].a, &que[i].b);
                if (que[i].a > que[i].b) {
                    swap(que[i].a , que[i].b);  //小号在前
                }
                que[i].m = 1;
                mp[que[i].a * N + que[i].b] = 1;  //被毁标记
            }
            else {
                scanf("%d", &que[i].a);
                que[i].m = 0;
            }
        }
        for (int i = 0; i < m; i++) {
            if (!mp[edge[i].a * N + edge[i].b]) {  //未被毁则合并
                unite(edge[i].a, edge[i].b);
            }
        }
        int ansn = 0;
        for (int i = q - 1; i >= 0; i--) {
            if (que[i].m) {
                unite(que[i].a, que[i].b);  //被毁的连回去
            }
            else {
                int t = findfa(que[i].a);
                if (pw[t] <= pw[que[i].a]) {  //根的power不比自己大
                    ans[ansn++] = -1;
                }
                else {
                    ans[ansn++] = t;
                }
            }
        }
        for (int i = ansn - 1; i >= 0; i--) {
            printf("%d\n", ans[i]);
        }
    }
    return 0;
}