Submission #1750334

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define LL long long
int n, m;
const int N = 200000;
vector <int> bi[N], bb[N];
int col[N], cnt[3], all;
LL ans; int nw;
void dfs(int t, int c)
{
    if (col[t] == -1)
    {
        col[t] = c;
        cnt[c] ++;
    }
    else
    {
        if (col[t] != c) all = 1;
        return;
    }
    for (int i = 0; i < bi[t].size(); ++ i)
        dfs(bi[t][i], (c + 1) % 3), nw ++;
    for (int i = 0; i < bb[t].size(); ++ i)
        dfs(bb[t][i], (c + 2) % 3);
}
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= m; ++ i)
    {
        int a, b;
        scanf("%d%d", &a, &b);
        bi[a].push_back(b);
        bb[b].push_back(a);
    }
    for (int i = 1; i <= n; ++ i) col[i] = -1;
    for (int i = 1; i <= n; ++ i) if (col[i] == -1)
    {
        cnt[0] = cnt[1] = cnt[2] = 0;
        all = nw = 0;
        dfs(i, 0);
        if (all) ans += 1ll * (cnt[0] + cnt[1] + cnt[2]) * (cnt[0] + cnt[1] + cnt[2]);
        else if (cnt[0] && cnt[1] && cnt[2])
            ans += 1ll * cnt[0] * cnt[1] + 1ll * cnt[0] * cnt[2] + 1ll * cnt[1] * cnt[2];
        else ans += nw;
    }
    printf("%lld\n", ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:28:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
                          ^
./Main.cpp:32:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &a, &b);
                              ^

Judge Result