QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#447556#7404. Back and ForthCryingWA 4ms3864kbC++142.6kb2024-06-18 16:18:562024-06-18 16:18:57

Judging History

你现在查看的是最新测评结果

  • [2024-06-18 16:18:57]
  • 评测
  • 测评结果:WA
  • 用时:4ms
  • 内存:3864kb
  • [2024-06-18 16:18:56]
  • 提交

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

Tip: Click on the bar to expand more detailed information

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'