Submission #931456

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Source Code Expand

#include<stdio.h>
#include<algorithm>
#include<vector>
using namespace std;
int n, m, K, Num[60], cnt, Up[60], Ch[60][60];
int C, D[60], D2[60], Root[60];
long long Mod = 1000000007, po[110];
vector<int>E[60];
void DFS(int a){
    int i, x;
    Num[a] = ++cnt;
    Up[a] = cnt;
    for(i=0;i<E[a].size();i++){
        x = E[a][i];
        if(Num[x]){
            Up[a] = min(Up[a], Num[x]);
            continue;
        }
        Ch[a][x] = 1;
        DFS(x);
        Up[a] = min(Up[a], Up[x]);
        if(Up[x] >= Num[a]){
            Ch[a][x] = 2;
        }
    }
}
void Do(int a, int pp, int c){
    int i, x;
    for(i=0;i<E[a].size();i++){
        x = E[a][i];
        if(x==pp)continue;
        if(Num[x] < Num[a]){
            D2[c]++;
            continue;
        }
        if(!Ch[a][x])continue;
        if(Ch[a][x] == 1){
            D[c]++,D2[c]++;
            Do(x, a, c);
        }
        else{
            C++;
            D[C]=2,D2[C] = 1;
            Do(x, a, C);
        }
    }
}
int gcd(int a, int b){
    return b?gcd(b,a%b):a;
}
long long Inv(long long a){
    int b = Mod-2;
    long long r = 1;
    while(b){
        if(b&1)r=r*a%Mod;
        a=a*a%Mod;b>>=1;
    }
    return r;
}
int main(){
    int i, a, b, j;
    long long res = 1;
    scanf("%d%d%d",&n,&m,&K);
    for(i=0;i<m;i++){
        scanf("%d%d",&a,&b);
        E[a].push_back(b);
        E[b].push_back(a);
    }
    po[0]=1;
    for(i=1;i<=100;i++){
        po[i]=po[i-1]*K%Mod;
    }
    for(i=1;i<=n;i++){
        if(!Num[i]){
            DFS(i);
            Root[i] = 1;
        }
    }
    for(i=1;i<=n;i++){
        if(Root[i]){
            Do(i,-1,0);
        }
    }
    for(i=1;i<=C;i++){
        if(D2[i] == D[i] - 1){
            res = res * po[D2[i]] % Mod;
            continue;
        }
        if(D2[i] != D[i]){
            for(j=1;j<=D2[i];j++){
                res = res * (K-1+j)%Mod;
                res = res * Inv(j)%Mod;
            }
        }
        else{
            long long s = 0;
            for(j=1;j<=D[i];j++){
                s = (s+po[gcd(j,D[i])])%Mod;
            }
            s = s * Inv(D[i])%Mod;
            res = res * s %Mod;
        }
    }
    printf("%lld\n",res);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:63:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d",&n,&m,&K);
                             ^
./Main.cpp:65:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&a,&b);
                            ^

Judge Result