Submission #661185

#	Time	Username	Problem	Language	Result	Execution time	Memory
661185		kinope	Olympic Bus (JOI20_ho_t4)	C++14	37 / 100	1089 ms	15896 KiB

ho_t4

#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;
typedef long long ll;
typedef pair<ll, int> pii;
struct st{int a, b; ll c, d;} kraw[50000];

vector<pii> g[201][2];
ll odl[4][201][201]; //0. to z 1 do innych, 1. to z n do innych, 2. to z innych do 1, 3. to z innych do n

void dijkstra(int s, int y, int b, bool ODWR){
		priority_queue<pii> pq;
		pq.emplace(0, s);
		odl[b][s][y] = 0;
		while(!pq.empty()){
				int x = pq.top().ss; ll dis = -pq.top().ff;
				pq.pop();
				for(pii u : g[x][ODWR]){
						if(u.ss == y) continue;
						if(odl[b][u.ss][y] > dis + u.ff){
								odl[b][u.ss][y] = dis + u.ff;
								pq.emplace(-odl[b][u.ss][y], u.ss);
						}
				}
		}
}

int main(){
		
		int n, m, a, b; ll c, d;
		scanf("%d%d", &n, &m);
		for(int i = 0; i <= n; ++i)
				for(int j = 0; j <= n; ++j) odl[0][i][j] = odl[1][i][j] = odl[2][i][j] = odl[3][i][j] = 1e18;
		
		for(int i = 0; i < m; ++i){
				scanf("%d%d%lld%lld", &a, &b, &c, &d);
				kraw[i] = {a, b, c, d};
				g[a][0].emplace_back(c, b);
				g[b][1].emplace_back(c, a);
		}
		
		for(int j = 0; j <= n; ++j) odl[0][1][j] = odl[1][n][j] = odl[2][1][j] = odl[3][n][j] = 0;
		
		for(int i = 2; i <= n; ++i) {dijkstra(1, i, 0, 0);} dijkstra(1, 0, 0, 0);
		for(int i = 1; i < n; ++i) {dijkstra(n, i, 1, 0);} dijkstra(n, 0, 1, 0); 
		for(int i = 2; i <= n; ++i) dijkstra(1, i, 2, 1);
		for(int i = 1; i < n; ++i) dijkstra(n, i, 3, 1); 
		multiset<ll> s[201][4]; //0. to z 1 do x, 1. to z n do x, 2. to z x do 1, 3. to z x do n
		
		for(int i = 0; i < m; ++i){
				a = kraw[i].a, b = kraw[i].b, c = kraw[i].c;
				s[b][0].emplace(odl[0][a][b] + c);
				s[b][1].emplace(odl[1][a][b] + c);
				s[a][2].emplace(odl[2][b][a] + c);
				s[a][3].emplace(odl[3][b][a] + c);
				//printf("%lld %lld %lld %lld\n", odl[0][a][b], odl[1][a][b], odl[2][b][a], odl[3][b][a]);
		}
		
		ll wynik = 1e18;
		
		for(int i = 0; i < m; ++i){
				a = kraw[i].a, b = kraw[i].b, c = kraw[i].c, d = kraw[i].d;
				
				ll tmp = c + odl[0][a][b];
				multiset<ll>::iterator it = s[b][0].find(tmp); s[b][0].erase(it);
				tmp = c + odl[1][a][b];
				it = s[b][1].find(tmp); s[b][1].erase(it);
				
				tmp = c + odl[2][a][b]; s[b][2].emplace(tmp);
				tmp = c + odl[3][a][b]; s[b][3].emplace(tmp);
				
				ll t0 = 1e18, t1 = 1e18, t2 = *s[b][2].begin(), t3 = *s[b][3].begin();
				if(s[b][0].size()) t0 = *s[b][0].begin();
				if(s[b][1].size()) t1 = *s[b][1].begin();
				
				if(b == 1) t0 = t2 = 0;
				if(b == n) t1 = t3 = 0;
				
				wynik = min(wynik, t0 + t3 + t1 + t2 + d);
				wynik = min(wynik, t0 + t3 + odl[1][1][b] + d);
				wynik = min(wynik, odl[0][n][b] + t1 + t2 + d);
				
				//printf("%lld %lld %lld %lld\n", t0, t1, t2, t3);
				
				tmp = c + odl[2][a][b];
				it = s[b][2].find(tmp); s[b][2].erase(it);
				tmp = c + odl[3][a][b];
				it = s[b][3].find(tmp); s[b][3].erase(it);
				
				tmp = c + odl[0][a][b]; s[b][0].emplace(tmp);
				tmp = c + odl[1][a][b]; s[b][1].emplace(tmp);
		}
		wynik = min(wynik, odl[0][n][0] + odl[1][1][0]);
		
		if(wynik != 1e18) printf("%lld\n", wynik);
		else printf("-1");
		
		
		return 0;
}

Compilation message (stderr)

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:32:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   scanf("%d%d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~
ho_t4.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d%d%lld%lld", &a, &b, &c, &d);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 21 / 21
• Subtask 4: 0 / 63