Submission #1286208

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define FOR(i, n) for(int i = 0; i < (n); i++)
#define MEM(a, x) memset(a, x, sizeof(a))
#define ALL(a) a.begin(), a.end()
#define UNIQUE(a) a.erase(unique(ALL(a)), a.end())
typedef long long ll;
typedef pair<int, ll> P;

int n, m;
vector<P> g[1005];
vector<P> v[1005];
bool used[2005];
ll ma[1005];

void dfs(int s, ll c) {
	FOR(i, g[s].size()) {
		P t = g[s][i];
		ma[t.first] = max(ma[t.first], c + t.second);
		dfs(t.first, c + t.second);
	}
}

bool check(int s) {
	FOR(i, v[s].size()) {
		P t = v[s][i];
		if (used[t.second]) return false;
		used[t.second] = true;
		return check(t.first);
	}
	return true;
}

int main(int argc, char const *argv[]) {
	ios_base::sync_with_stdio(false);
	cin >> n >> m;
	FOR(i, m) {
		int a, b;
		ll c;
		cin >> a >> b >> c;
		a--;
		b--;
		g[a].push_back(P(b, c));
		v[a].push_back(P(b, i));
	}

	if (!check(0)) {
		cout << "inf" << endl;
		return 0;
	}
	fill(ma, ma + n, -100000000000000);
	ma[0] = 0;
	dfs(0, 0);
	cout << ma[n-1] << endl;
	return 0;
}

Submission Info

Judge Result