QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#447556 | #7404. Back and Forth | Crying | WA | 4ms | 3864kb | C++14 | 2.6kb | 2024-06-18 16:18:56 | 2024-06-18 16:18:57 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
typedef long ll;
typedef array<int,2> pr;
const int MAXN = 210,INF = 1e8;
void tomin(int& x,int y){x = min(x,y);}
void tomax(int& x,int y){x = max(x,y);}
int T,n,m,s,t,p[MAXN];
vector<int> e[MAXN];
int dis[MAXN][MAXN],tag[MAXN];
int dp[MAXN][MAXN],tmp[MAXN][MAXN],vis[MAXN][MAXN],visg[MAXN][MAXN],ans;
int chk(int x,int y){return x!=s && x!=t && y!=s && y!=t;}
void solve(){
cin>>n>>m>>s>>t; ans = INF;
for(int i=1;i<=n;i++)cin>>p[i],e[i].clear();
for(int i=1,u,v;i<=m;i++)cin>>u>>v,e[u].push_back(v);
assert(s != t);
for(int i=1;i<=n;i++){
int* f = dis[i]; fill(f+1,f+1+n,INF); fill(tag+1,tag+1+n,0);
priority_queue<pr> pq;
f[i] = p[i],pq.push((pr){-f[i],i});
while(pq.size()){
int u = pq.top()[1]; pq.pop(); if(tag[u]++)continue;
for(auto v : e[u])if(f[v] > f[u]+p[v])f[v] = f[u]+p[v],pq.push((pr){-f[v],v});
}
}
if(dis[s][t] == INF || dis[t][s] == INF)return void(cout<<"-1\n");
//
for(int x=1;x<=n;x++)for(int y=1;y<=n;y++)dp[x][y] = INF,vis[x][y] = 0;
for(int x=1;x<=n;x++)for(int y=1;y<=n;y++)tmp[x][y] = INF,visg[x][y] = 0;
//初始化
tomin(ans,dis[s][t] + dis[t][s] - (p[s] + p[t]));
for(int x=1;x<=n;x++){
for(int y=1;y<=n;y++)if(chk(x,y) && x!=y){
tomin(dp[x][y],dis[x][y]+dis[y][t]+dis[t][x]-(p[x]+p[y]+p[t]));
}
if(chk(x,x))dp[x][x] = dis[x][t] + dis[t][x] - (p[x] + p[t]);
}
//dijkstra
while(1){
int vx = -1,vy = -1,wx = -1,wy = -1;
for(int x=1;x<=n;x++)for(int y=1;y<=n;y++)if(!vis[x][y] && dp[x][y] != INF){
if(vx==-1 || dp[vx][vy] > dp[x][y])vx = x,vy = y;
}
for(int x=1;x<=n;x++)for(int y=1;y<=n;y++)if(!visg[x][y] && tmp[x][y] != INF){
if(wx==-1 || tmp[wx][wy] > tmp[x][y])wx = x,wy = y;
}
if(vx==-1 && wx==-1)break;
if(wx==-1 || (vx!=-1 && dp[vx][vy] < tmp[wx][wy])){
int x = vx,y = vy,val = dp[x][y];
if(vis[x][y]++)continue;
tomin(ans,val+dis[s][x]+dis[y][s]-(p[x]+p[y]+p[s]));
//
for(int cx=1;cx<=n;cx++)if(chk(cx,y) && y!=cx){
tomin(tmp[x][cx],val+dis[y][cx]-p[y]-p[cx]);
}
}else{
int x = wx,cx = wy,val = tmp[x][cx];
if(visg[x][cx]++)continue;
for(int cy=1;cy<=n;cy++)if(chk(cx,cy) && x!=cy){
tomin(dp[cx][cy],val+dis[cy][x]-p[x]-p[cy]);
}
}
}
cout<<ans<<endl;
}
int main(){
cin>>T;
while(T--)solve();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3820kb
input:
3 4 5 1 4 1 1 1 1 1 2 2 3 3 1 4 2 3 4 4 4 1 2 1 1 1 1 1 2 2 3 3 4 4 1 4 8 1 3 1 100 1 1 1 2 2 1 2 3 3 2 1 4 4 1 3 4 4 3
output:
4 4 3
result:
ok 3 number(s): "4 4 3"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3836kb
input:
1 2 0 1 2 1 1
output:
-1
result:
ok 1 number(s): "-1"
Test #3:
score: -100
Wrong Answer
time: 4ms
memory: 3864kb
input:
10 20 40 5 16 2 1 1 1 2 1 1 2 1 1 1 2 1 1 1 2 1 2 1 2 7 2 8 5 15 4 17 13 11 6 9 2 12 13 12 1 1 8 2 20 6 9 18 3 2 15 10 12 4 17 11 5 19 15 15 9 14 7 11 2 1 15 16 1 13 3 11 16 5 10 19 6 1 3 13 14 20 11 6 19 7 9 20 12 17 18 13 9 4 18 3 19 13 17 19 9 19 10 8 6 20 40 10 1 2 2 2 2 1 2 1 2 2 2 2 2 1 2 2 1 ...
output:
12 7 11 10 10 5 6 13 9 12
result:
wrong answer 1st numbers differ - expected: '15', found: '12'