HDU 1863 畅通工程 （最小生成树）

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1 2 1
1 3 2
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1 3
2 3 2
0 100

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很水的最小生成树。

#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <math.h>
#include <stack>
#define lson o<<1, l, m
#define rson o<<1|1, m+1, r
using namespace std;
typedef long long LL;
const int maxn = 105;
const int mod = 1000000007;
int n, m, fa[maxn];
struct C {
    int st, en, v;
}ed[maxn];
bool cmp(C x, C y) {
    return x.v < y.v;
}
int Find(int x) {
    return x == fa[x] ? x : x = Find(fa[x]);
}
int main()
{
    while(~scanf("%d%d", &n, &m) && n) {
        for(int i = 1; i <= n; i++ ) {
            int a, b, c;
            scanf("%d%d%d", &a, &b, &c);
            ed[i].st = a;
            ed[i].en = b;
            ed[i].v = c;
        }
        sort(ed+1, ed+n+1, cmp);
        int cnt = 0, sum = 0;
        for(int i = 1; i <= m; i++) fa[i] = i;
        for(int i = 1; i <= n; i++){
            int pres = Find(ed[i].st), pree = Find(ed[i].en);
            if(pres != pree) {
                fa[pres] = pree;
                cnt++;
                sum += ed[i].v;
                if(cnt == m-1) break;
            }
        }
        if(cnt == m-1) printf("%d\n", sum);
        else printf("?\n");
    }
    return 0;
}

HDU 1863 畅通工程 （最小生成树）,布布扣,bubuko.com

HDU 1863 畅通工程 （最小生成树）

原文：http://blog.csdn.net/u013923947/article/details/38461711