Submission #101422

#	Time	Username	Problem	Language	Result	Execution time	Memory
101422		jamielim	Tracks in the Snow (BOI13_tracks)	C++14	49.69 / 100	2101 ms	16380 KiB

tracks

#include <bits/stdc++.h>
using namespace std;

int main(){
    int h,w;
    scanf("%d%d",&h,&w);
    char grid[h+5][w+5];
    for(int i=0;i<h;i++){
        scanf("%s",grid[i]);
    }
    int r=0,f=0;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(grid[i][j]=='R')r++;
            else if(grid[i][j]=='F')f++;
        }
    }
    int ans=1;
    queue<pair<int,int> > q;
    int dx[]={0,0,1,-1},dy[]={1,-1,0,0};
    while(r!=0&&f!=0){
        ans++;
        q.push(make_pair(0,0));
        if(grid[0][0]=='R'){
            while(!q.empty()){
                pair<int,int> cur=q.front();q.pop();
                for(int i=0;i<4;i++){
                    int nx=cur.first+dx[i],ny=cur.second+dy[i];
                    if(0<=nx&&nx<h&&0<=ny&&ny<w&&grid[nx][ny]=='R'){
                        grid[nx][ny]='F';
                        r--; f++;
                        q.push(make_pair(nx,ny));
                    }
                }
            }
        }else{
            while(!q.empty()){
                pair<int,int> cur=q.front();q.pop();
                for(int i=0;i<4;i++){
                    int nx=cur.first+dx[i],ny=cur.second+dy[i];
                    if(0<=nx&&nx<h&&0<=ny&&ny<w&&grid[nx][ny]=='F'){
                        grid[nx][ny]='R';
                        f--; r++;
                        q.push(make_pair(nx,ny));
                    }
                }
            }
        }
    }
    printf("%d",ans);
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:6:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&h,&w);
     ~~~~~^~~~~~~~~~~~~~
tracks.cpp:9:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s",grid[i]);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 19.6875 / 70