UVALive 6467 Strahler Order 拓扑排序

这题是今天下午BNU SUMMER TRAINING的C题

是队友给的解题思路，用拓扑排序然后就可以了

最后是3A

其中两次RE竟然是因为：

scanf("%d",mm);

ORZ

以后能用CIN还是CIN吧　　QAQ

贴代码了：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <iostream>
#include <stack>
#include <queue>
#include <algorithm>

#define ll long long
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 8000;
int indgree[MAXN], map[MAXN][MAXN], ans[MAXN], cur[MAXN][MAXN];
int n;
void init(){
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= n; ++j){
            map[i][j] = i == j ? 0 : INF;
        }
    }
    memset(indgree, 0, sizeof(indgree));
    memset(ans, 0, sizeof(ans));
    memset(cur, 0, sizeof(cur));
}

void insert_cur(int x, int num){
    int pos = 1;
    while(1){
        if(cur[x][pos] == 0){
            cur[x][pos] = num;
            break;
        }
        ++pos;
    }
}

int sigma_cur(int x){
    int temp_ans = 0;
    int Max = -INF;
    for(int i = 1; cur[x][i] != 0; ++i){
        if(cur[x][i] > Max) Max = cur[x][i];
    }
    int flag = 0;
    for(int i = 1; cur[x][i] != 0; ++i){
        if(cur[x][i] == Max)    ++flag;
    }
    if(flag >= 2)   ans[x] = ++Max;
    else if(flag == 1)  ans[x] = Max;
    return ans[x];
}

void topsort(){
    int i, j;
    while(1){
        for(i = 1; i <= n; ++i)
            if(indgree[i] == 0)  break;
        if(i != n + 1){
            for(j = 1; j <= n; ++j)
                if(map[i][j] == 1){
                    map[i][j] = 0;
                    --indgree[j];
                    insert_cur(j, ans[i]);
                    if(indgree[j] == 0) ans[j] = sigma_cur(j);
                }
            indgree[i] = -1;//pop i
        }
        else break;
    }
}

int main(){
    int i, j, k, p, mm, a, b;
    scanf("%d",&mm);
    int numCase = 0;
    while(mm--){
        init();
        scanf("%d%d%d",&k,&n,&p);
        while(p--){
            scanf("%d%d",&a,&b);
            ++indgree[b];
            map[a][b] = 1;
        }
        for(i = 1; i <= n; ++i){
            if(indgree[i] == 0) ans[i] = 1;
        }
        topsort();
        printf("%d %d
",++numCase,ans[n]);
    }
    return 0;
}