hdu 1856并查集

很简单的并查集,不过第一次交居然超内存,把height数组改为short int就过了~~

/*
 * hdu1856/win.cpp
 * Created on: 2012-7-18
 * Author    : ben
 */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
const int MAXM = 10000010;
int myset[MAXM], mysum[MAXM];
short int myheight[MAXM];
int N, M = MAXM - 1, ans;
inline int mymax(int a, int b) {
    return a > b ? a : b;
}
void initset() {
    for(int i = 0; i <= M; i++) {
        myset[i] = i;
        myheight[i] = 1;
        mysum[i] = 1;
    }
}
int myfind(int x) {
    while (myset[x] != x) {
        x = myset[x];
    }
    return x;
}
void mymerge(int a, int b) {
    if(myheight[a] == myheight[b]) {
        myheight[a]++;
        myset[b] = a;
        mysum[a] += mysum[b];
        ans = mymax(ans, mysum[a]);
    }else if(myheight[a] < myheight[b]) {
        myset[a] = b;
        mysum[b] += mysum[a];
        ans = mymax(ans, mysum[b]);
    }else {
        myset[b] = a;
        mysum[a] += mysum[b];
        ans = mymax(ans, mysum[a]);
    }
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int a, b;
    while(scanf("%d", &N) == 1) {
        initset();
        ans = 1;
        for(int i = 0; i < N; i++) {
            scanf("%d%d", &a, &b);
            a = myfind(a);
            b = myfind(b);
            if(a != b) {
                mymerge(a, b);
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}
posted @ 2012-07-19 13:21  moonbay  阅读(192)  评论(0编辑  收藏  举报