bzoj 1016 JSOI2008 最小生成树计数

    我都不忍心吐槽了。

    这么水的暴力我一开始竟然想写链剖！！！

    对于某个权值，相同的边不会超过10条。于是，暴力，然后乘起来。

    注意特判！特判！图不连通的时候输出0。

    我的程序在不联通的时候会输出奇怪的数字……要崩溃了……

    上代码：

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

#include <cstdlib>

#include <cmath>

#define N 111

#define M 1011

#define yu 31011

#define inf 0x7f7f7f7f

using namespace std;



struct sss

{

    int x, y;

    int val;

}bian[M];

int n, m;

int fa[N];

int use[M] = {0}, same[15], samenum = 0;

long long ans = 1, minval;



bool cmp(sss x, sss y) { return x.val < y.val; }



int find(int x)

{

    if (fa[x] == x) return x;

    fa[x] = find(fa[x]);

    return fa[x];

}



long long kru()

{

    long long nowval = 0; int nowc = n;

    for (int i = 1; i <= n; ++i) fa[i] = i;

    for (int i = 1; i <= m; ++i)

    {

        int x = find(bian[i].x);

        int y = find(bian[i].y);

        if (use[i] == 1 && x == y) return 0; // use[i] == 1 用 2 不用 

        if (use[i] == 2) continue;

        if (x != y)

        {

            fa[x] = y;

            nowval += bian[i].val;

            nowc --;

        }

    }

    if (nowc != 1) return 0;

    else return nowval;

}



int main()

{

    scanf("%d%d", &n, &m);

    for (int i = 1; i <= m; ++i)

        scanf("%d%d%d", &bian[i].x, &bian[i].y, &bian[i].val);

    sort(bian+1, bian+1+m, cmp);

    bian[0].val = -inf; bian[m+1].val = -inf;

    minval = kru();

    if (minval == 0)

    {

        printf("0\n");

        return 0;

    }

    for (int w = 1; w <= m; ++w)

    {

        samenum = 0;

        if (bian[w].val != bian[w+1].val) continue;

        same[++samenum] = w++;

        while (bian[w].val == bian[w-1].val) {same[++samenum] = w++;}

        w--;

        int zans = 0;

        int cou = (1 << samenum)-1;

        for (int i = 0; i <= cou; ++i)

        {

            int j = i, thisb = 1;

            for (int k = 1; k  <= samenum; ++k) use[same[k]] = 2;

            while (j){if (j & 1) use[same[thisb]] = 1;j >>= 1; thisb++;}

            if (kru() == minval) zans++;

        }

        for (int i = 1; i <= samenum; ++i) use[same[i]] = 0;

        ans *= (zans%yu);

        ans %= yu;

    }

    printf("%lld\n", ans%yu);

    return 0;

}