Submission #2233697

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Source Code Expand

# include <iostream>
# include <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
# include <tuple>
# include <unordered_map>
# include <numeric>
# include <complex>
# include <bitset>
# include <random>
# include <chrono>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
typedef pair<LL, LL> P;
constexpr int INF = 2000000000;
constexpr int HINF = INF / 2;
constexpr double DINF = 100000000000000000.0;
constexpr long long LINF = 9223372036854775807;
constexpr long long HLINF = 4500000000000000000;
const double PI = acos(-1);
int dx[4] = { 0,1,0,-1 }, dy[4] = { 1,0,-1,0 };
# define ALL(x)      (x).begin(),(x).end()
# define UNIQ(c)     (c).erase(unique(ALL((c))),(c).end())
# define mp          make_pair
# define eb          emplace_back
# define FOR(i,a,b)  for(int i=(a);i<(b);i++)
# define RFOR(i,a,b) for(int i=(a);i>=(b);i--)
# define REP(i,n)    FOR(i,0,n)
# define INIT        std::ios::sync_with_stdio(false);std::cin.tie(0)

const int MAX_V = 101010;

struct edge { int to, cap, rev; };

vector<edge> G[MAX_V];
int level[MAX_V];
int iter[MAX_V];

void add_edge(int from, int to, int cap) {
	G[from].emplace_back(edge{ to,cap,(int)G[to].size() });
	G[to].emplace_back(edge{ from,0,(int)G[from].size() - 1 });
}

void bfs(int s) {
	REP(i, MAX_V)level[i] = -1;
	queue<int> que;
	level[s] = 0;
	que.push(s);
	while (!que.empty()) {
		int v = que.front();
		que.pop();
		REP(i, G[v].size()) {
			edge &e = G[v][i];
			if (e.cap > 0 && level[e.to] < 0) {
				level[e.to] = level[v] + 1;
				que.push(e.to);
			}
		}
	}
}

int dfs(int v, int t, int f) {
	if (v == t)return f;
	for (int &i = iter[v]; i < G[v].size(); i++) {
		edge &e = G[v][i];
		if (e.cap > 0 && level[v] < level[e.to]) {
			int d = dfs(e.to, t, min(f, e.cap));
			if (d > 0) {
				e.cap -= d;
				G[e.to][e.rev].cap += d;
				return d;
			}
		}
	}
	return 0;
}

int max_flow(int s, int t) {
	int flow = 0;
	for (;;) {
		bfs(s);
		if (level[t] < 0)return flow;
		REP(i, MAX_V)iter[i] = 0;
		int f;
		while ((f = dfs(s, t, INF)) > 0) {
			flow += f;
		}
	}
}


int n, m, p, g;
int l;
int main() {
	int s = 1234;
	cin >> n >> m >> p >> g;
	REP(i, g) {
		cin >> l;
		add_edge(s, l, HINF);
	}
	REP(i, n) {
		int a, b, c;
		cin >> a >> b >> c;
		add_edge(a, b, c);
	}
	cout << (max_flow(s, 0)>=p?"Yes":"No") << endl;
}

Submission Info

Judge Result