oj.uz

Submission #202606

# Submission time Handle Problem Language Result Execution time Memory
202606 2020-02-17T09:09:57 Z dndhk Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 1000 ms 3320 KB 
#include <bits/stdc++.h>

#define pb push_back

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAX_N = 200;
const int MAX_M = 50000;
const ll INF = 1e14;

int N, M;
vector<pii> gp[2][MAX_N+1];
int u[MAX_M+1], v[MAX_M+1];
ll d[MAX_M+1], c[MAX_M+1];
ll dp[2][2][MAX_N+1];

ll ans;
vector<int> vt;

int ST;

priority_queue<pll, vector<pll>, greater<pll> > pq;

bool vst[MAX_N+1];
int from[MAX_N+1];

void solve(int x, int y){
	for(int i=1; i<=N; i++){
		dp[x][y][i] = INF;
		vst[i] = false;
		from[i] = 0;
	}
	dp[x][y][ST] = 0;
	pq.push({0LL, (ll)ST});
	while(!pq.empty()){
		pll now = pq.top(); pq.pop();
		if(vst[now.second])	continue;
		vst[now.second] = true;
		if(from[now.second]!=0){
			vt.pb(from[now.second]);
		}
		for(pii p : gp[x][now.second]){
			if(dp[x][y][p.first]>dp[x][y][now.second] + c[p.second]){
				from[p.first] = now.second;
				dp[x][y][p.first] = dp[x][y][now.second] + c[p.second];
				pq.push({dp[x][y][p.first], p.first});
			}
		}
	}
}

bool chk[MAX_M+1];

vector<pii> gp2[MAX_N+1];

ll dp2[MAX_N+1], dp3[MAX_N+1];

void solve2(int x){
	for(int i=1; i<=N; i++){
		while(!gp2[i].empty())	gp2[i].pop_back();
		dp2[i] = dp3[i] = INF;
		vst[i] = false;
	}
	for(int i=1; i<=M; i++){
		if(i!=x){
			gp2[u[i]].pb({v[i], (int)c[i]});
		}else{
			gp2[v[i]].pb({u[i], (int)c[i]});
		}
	}
	pq.push({0LL, 1LL});
	dp2[1] = 0;
	while(!pq.empty()){
		pll now = pq.top(); pq.pop();
		if(vst[now.second])	continue;
		vst[now.second] = true;
		for(pii p : gp2[now.second]){
			if(dp2[p.first]>dp2[now.second] + (ll)p.second){
				dp2[p.first] = dp2[now.second] + (ll)p.second;
				pq.push({dp2[p.first], p.first});
			}
		}
	}
	for(int i=1; i<=N; i++)	vst[i] = false;
	pq.push({0LL, (ll)N});
	dp3[N] = 0;
	while(!pq.empty()){
		pll now = pq.top(); pq.pop();
		if(vst[now.second])	continue;
		vst[now.second] = true;
		for(pii p : gp2[now.second]){
			if(dp3[p.first]>dp3[now.second] + (ll)p.second){
				dp3[p.first] = dp3[now.second] + (ll)p.second;
				pq.push({dp3[p.first], p.first});
			}
		}
	}
	//cout<<x<<" "<<dp2[N]<<" "<<dp3[1]<<" "<<d[x]<<endl;
	ans = min(ans, dp2[N] + dp3[1] + d[x]);
}


int main(){
	scanf("%d%d", &N, &M);
	for(int i=1; i<=M; i++){
		scanf("%d%d%lld%lld", &u[i], &v[i], &c[i], &d[i]);
		gp[0][u[i]].pb({v[i], i});
		gp[1][v[i]].pb({u[i], i});
	}
	ST = 1; solve(0, 0); ST = N; solve(0, 1);
	ST = 1; solve(1, 0); ST = N; solve(1, 1);
	for(int i : vt){
		if(!chk[i]){
			solve2(i);
			chk[i] = true;
		}
	}
	/*for(int i=0; i<2; i++){
		for(int j=0; j<2; j++){
			for(int k=1; k<=N; k++){
				cout<<dp[i][j][k]<<" ";
			}
			cout<<endl;
		}
	}*/
	ans = dp[0][0][N] + dp[0][1][1];
	for(int i=1; i<=M; i++){
		if(!chk[i]){
			solve2(i);
			// ll dist = d[i];
			// if(dp[0][0][u[i]]<=dp[0][0][v[i]])	dist+=dp[0][0][N];
			// else	dist+=min(dp[0][0][N], dp[0][0][v[i]] + c[i] + dp[1][1][u[i]]);
			// if(dp[0][1][u[i]]<=dp[0][1][v[i]])	dist+=dp[0][1][1];
			// else	dist+=min(dp[0][1][1], dp[0][1][v[i]] + c[i] + dp[1][0][u[i]]);
			// // cout<<u[i]<<" "<<v[i]<<" "<<c[i]<<" "<<d[i]<<endl;
			// // cout<<dp[0][0][v[i]]<<" "<<dp[1][1][u[i]]<<" "<<dp[0][1][v[i]]<<" "<<dp[1][0][u[i]]<<endl;
			// ans = min(ans, dist);
		}
	}
	if(ans>=INF){
		printf("-1");
	}else{
		printf("%lld\n", ans);
	}
	return 0;
}

Compilation message

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:108:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &M);
  ~~~~~^~~~~~~~~~~~~~~~
ho_t4.cpp:110:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%lld%lld", &u[i], &v[i], &c[i], &d[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 504 KB Output is correct
2 Correct 6 ms 380 KB Output is correct
3 Correct 63 ms 504 KB Output is correct
4 Correct 67 ms 504 KB Output is correct
5 Correct 27 ms 376 KB Output is correct
6 Correct 6 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 18 ms 376 KB Output is correct
10 Correct 94 ms 504 KB Output is correct
11 Correct 88 ms 376 KB Output is correct
12 Correct 89 ms 376 KB Output is correct
13 Correct 39 ms 376 KB Output is correct
14 Correct 46 ms 376 KB Output is correct
15 Incorrect 43 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1098 ms 3320 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 376 KB Output is correct
2 Correct 6 ms 376 KB Output is correct
3 Execution timed out 1092 ms 2552 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 504 KB Output is correct
2 Correct 6 ms 380 KB Output is correct
3 Correct 63 ms 504 KB Output is correct
4 Correct 67 ms 504 KB Output is correct
5 Correct 27 ms 376 KB Output is correct
6 Correct 6 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 18 ms 376 KB Output is correct
10 Correct 94 ms 504 KB Output is correct
11 Correct 88 ms 376 KB Output is correct
12 Correct 89 ms 376 KB Output is correct
13 Correct 39 ms 376 KB Output is correct
14 Correct 46 ms 376 KB Output is correct
15 Incorrect 43 ms 376 KB Output isn't correct
16 Halted 0 ms 0 KB -