Submission #793176

#	Time	Username	Problem	Language	Result	Execution time	Memory
793176		peijar	Graph (BOI20_graph)	C++17	100 / 100	107 ms	16892 KiB

Graph

#include <iostream>
#include <fstream>
#include <cstdio>
#include <iomanip>
#include <sstream>
#include <cstring>
#include <string>
#include <cmath>
#include <stack>
#include <list>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <vector>
#include <algorithm>
#include <numeric>
#include <utility>
#include <functional>
#include <limits>
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int,int> pii;
typedef vector<vector<int> > graph;
 
const double pi = acos(-1.0);
 
#define oned(a, x1, x2) { cout << #a << ":"; for(int _i = (x1); _i < (x2); _i++){ cout << " " << a[_i]; } cout << endl; }
#define twod(a, x1, x2, y1, y2) { cout << #a << ":" << endl; for(int _i = (x1); _i < (x2); _i++){ for(int _j = (y1); _j < (y2); _j++){ cout << (_j > y1 ? " " : "") << a[_i][_j]; } cout << endl; } }
 
#define mp make_pair
#define pb push_back
#define fst first
#define snd second
 
const int MAXN = 200005;
 
int n, m;
vector<pii> g[MAXN];
 
int vis[MAXN];
int sgn[MAXN];
int val[MAXN];
 
queue<int> Q;
 
int ans[MAXN];
 
int cnt;
int comp[MAXN];
int num[MAXN];
 
void solve() {
	memset(vis,0,sizeof(vis));
	for(int u = 1; u <= n; u++) {
		if(!vis[u]) {
			vis[u] = true;
			sgn[u] = +1;
			val[u] = 0;
			cnt = 0;
			comp[cnt++] = u;
			bool bip = true;
			double x;
			Q.push(u);
			while(!Q.empty()) {
				int v = Q.front(); Q.pop();
				for(size_t i = 0; i < g[v].size(); i++) {
					int w = g[v][i].fst;
					int sum = g[v][i].snd;
					if(!vis[w]) {
						vis[w] = true;
						sgn[w] = -sgn[v];
						val[w] = sum-val[v];
						comp[cnt++] = w;
						Q.push(w);
					} else if(sgn[w]==sgn[v]) {
						bip = false;
						x = sgn[w]*(sum-val[w]-val[v])/2;
					}
				}
			}
			
			if(bip) {
				for(int i = 0; i < cnt; i++) {
					int v = comp[i];
					num[i] = (-sgn[v])*val[v];
				}
				sort(num,num+cnt);
				x = num[cnt/2];
			}
			
			for(int i = 0; i < cnt; i++) {
				int v = comp[i];
				ans[v] = val[v] + sgn[v]*x;
			}
			
			for(int i = 0; i < cnt; i++) {
				int v = comp[i];
				for(size_t i = 0; i < g[v].size(); i++) {
					int w = g[v][i].fst;
					if(ans[v]+ans[w]!=g[v][i].snd) {
						printf("NO\n");
						return;
					}
				}
			}
		}
	}
	
	printf("YES\n");
	for(int v = 1; v <= n; v++) {
		printf("%.1lf ", 0.5*ans[v]);
	}
	printf("\n");
}
 
int main() {
	//freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
	while(scanf("%d %d", &n, &m)==2) {
		for(int i = 1; i <= n; i++) {
			g[i].clear();
		}
		for(int i = 0; i < m; i++) {
			int a, b, c; scanf("%d %d %d", &a, &b, &c);
			c *= 2;
			g[a].pb(mp(b,c));
			g[b].pb(mp(a,c));
		}
		solve();
	}
}

Compilation message (stderr)

Graph.cpp: In function 'int main()':
Graph.cpp:128:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |    int a, b, c; scanf("%d %d %d", &a, &b, &c);
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 42 / 42