Submission #465712

#	Time	Username	Problem	Language	Result	Execution time	Memory
465712		MohamedFaresNebili	Portals (BOI14_portals)	C++14	31 / 100	1085 ms	49676 KiB

portals

#include <bits/stdc++.h>

using namespace std;

void solve()
{
    /// JUST KEEP GOING
    const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0};
    int n, m; cin>>n>>m; char grid[n][m]; int d[n][m];
    int sx, sy; int ex, ey;
    for(int l=0;l<n;l++) {
        for(int i=0;i<m;i++) {
            cin>>grid[l][i]; d[l][i]=1000000000;
            if(grid[l][i]=='S') {
                sx=l; sy=i; d[sx][sy]=0;
            }
            else if(grid[l][i]=='C') {
                ex=l; ey=i;
            }
        }
    }
    priority_queue<pair<int, pair<int, int>>>pq; pq.push({0, {sx, sy}});
    while(!pq.empty()) {
        int a=pq.top().second.first, b=pq.top().second.second, w=-pq.top().first; pq.pop();
        for(int l=0;l<4;l++) {
            int x=a+nx[l], y=b+ny[l];
            if(x>=0&&x<n&&y>=0&&y<m) {
                if(grid[x][y]=='#'||d[x][y]<d[a][b]+1) continue;
                d[x][y]=d[a][b]+1; pq.push({-d[x][y], {x, y}});
            }
        }
        int p=1000000000; vector<pair<int, int>>to;
        for(int l=0;l<4;l++) {
            int x=a, y=b; int k=0;
            while(x>=0&&y>=0&&x<n&&y<m&&grid[x][y]!='#') {
                x+=nx[l], y+=ny[l]; k++;
            }
          	x-=nx[l], y-=ny[l];
            p=min(p, k); to.push_back({x, y});
        }
		for(auto u:to) {
          int x=u.first, y=u.second;
          if(d[x][y]>d[a][b]+p) {
            d[x][y]=d[a][b]+p; pq.push({-d[x][y], {x, y}});
          }
        }
    }
    cout<<d[ex][ey]<<'\n';
}

int32_t main()
{

    int t; t=1;
    while(t--) {
        solve();
    }
    return 0;
}

Compilation message (stderr)

portals.cpp: In function 'void solve()':
portals.cpp:24:64: warning: unused variable 'w' [-Wunused-variable]
   24 |         int a=pq.top().second.first, b=pq.top().second.second, w=-pq.top().first; pq.pop();
      |                                                                ^
portals.cpp:48:22: warning: 'ex' may be used uninitialized in this function [-Wmaybe-uninitialized]
   48 |     cout<<d[ex][ey]<<'\n';
      |                      ^~~~
portals.cpp:48:22: warning: 'ey' may be used uninitialized in this function [-Wmaybe-uninitialized]

• Subtask 1: 11 / 11
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30