Submission #101838

#	Time	Username	Problem	Language	Result	Execution time	Memory
101838		rainy	Tracks in the Snow (BOI13_tracks)	C++14	21.67 / 100	2102 ms	299684 KiB

tracks

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int H,W;
char gr[4005][4005],ca,idk='a';
int vis[4005][4005];
int dx[]={0,1,0,-1},dy[]={1,0,-1,0};

void dfs(int x,int y){
    for(int i=0;i<4;i++){
        int nx=x+dx[i],ny=y+dy[i];
        if(0<=nx&&nx<H&&0<=ny&&ny<W){
            if(!vis[nx][ny]&&(gr[nx][ny]==ca||gr[nx][ny]==idk)){
                vis[nx][ny]=1;
                gr[nx][ny]=idk;
                dfs(nx,ny);
            }
        }
    }
}

int main(){
    scanf("%d%d",&H,&W);
    for(int i=0;i<H;i++){
        for(int j=0;j<W;j++)scanf(" %c",&gr[i][j]);
    }
    ca=gr[0][0];
    int ans=0;
    while(true){
        ans++;
        memset(vis,0,sizeof(vis));
        dfs(0,0);
        if(ca=='F')ca='R';
        else ca='F';
        bool isD=true;
        for(int i=0;i<H;i++){
            for(int j=0;j<W;j++){
                if(gr[i][j]=='F'||gr[i][j]=='R')isD=false;
            }
        }
        if(isD)break;
    }
    printf("%d\n",ans);
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&H,&W);
     ~~~~~^~~~~~~~~~~~~~
tracks.cpp:26:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         for(int j=0;j<W;j++)scanf(" %c",&gr[i][j]);
                             ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 21.666666666666668 / 30
• Subtask 2: 0 / 70