Submission #1365604

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Source Code Expand

#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
const int MAXN = 100005;
const int ESIZE = MAXN << 1;
int n, m;
int et = 1, fir[MAXN], to[ESIZE], ne[ESIZE], len[ESIZE];
int col[MAXN];
long long A[5], ans;

void link(int u, int v) {
    to[++et] = v, ne[et] = fir[u], fir[u] = et;
    to[++et] = u, ne[et] = fir[v], fir[v] = et;
    len[et - 1] = 1, len[et] = -1;
}

bool dfs(int o, int fa, int c) {
    A[col[o] = c]++, A[3]++; bool flag = 1;
    for (int i = fir[o]; i; i = ne[i]) {
        A[4]++;
        if (i != fa) {
            if (col[to[i]] == -1)
                flag &= dfs(to[i], i ^ 1, (c + len[i] + 3) % 3);
            else if (col[to[i]] != (c + len[i] + 3) % 3)
                flag = 0;
        }
    }
    return flag;
}

int main() {
    scanf("%d %d", &n, &m);
	for (int i = 1, x, y; i <= m; i++) {
		scanf("%d %d", &x, &y);
        link(x, y);
    }
    for (int i = 1; i <= n; i++)
        col[i] = -1;
    for (int i = 1, res; i <= n; i++)
        if (col[i] == -1) {
            A[0] = A[1] = A[2] = A[3] = A[4] = 0;
            res = dfs(i, 0, 0);
            if (res)
                ans += A[0] && A[1] && A[2] ? A[0] * A[1] + A[1] * A[2] + A[2] * A[0] : A[4] >> 1;
            else
                ans += A[3] * A[3];
        }
    printf("%lld", ans);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:33:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
                           ^
./Main.cpp:35:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
                         ^

Judge Result