Submission #42406

#	Time	Username	Problem	Language	Result	Execution time	Memory
42406		Hassoony	Tracks in the Snow (BOI13_tracks)	C++14	36.56 / 100	2151 ms	1048576 KiB

tracks

#include<bits/stdc++.h>
#include<unordered_map>
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef long double D;
const ll inf=(1ll<<61);
const ll mod=1e9+7;
const int MX=4002;
int n,m,cnt,h;
bool vis[MX][MX];
char a[MX][MX],c;
int dx[]={0,0,-1,1};
int dy[]={1,-1,0,0};
vector<pair<int,int> >nodes;
void dfs(int x,int y){
    if(vis[x][y])return;
    vis[x][y]=1;
    cnt++;
    nodes.push_back({x,y});
    for(int i=0;i<4;i++){
        int nx=dx[i]+x,ny=dy[i]+y;
        if(nx>=n||ny>=m||nx<0||ny<0||a[nx][ny]!=a[x][y])continue;
        dfs(nx,ny);
    }
    a[x][y]=c;
}
int main(){
    scanf("%d%d",&n,&m);
    for(int i=0;i<n;i++)scanf("%s",&a[i]);
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            if(a[i][j]!='.')h++;
        }
    }
    int ans=0;
    while(cnt!=h){
        c='R';
        if(a[0][0]=='R')c='F';
        cnt=0;
        dfs(0,0);
        ans++;
        for(auto pp:nodes)vis[pp.first][pp.second]=0;
        nodes.clear();
    }
    cout<<ans<<endl;
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:31:41: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[4002]' [-Wformat=]
     for(int i=0;i<n;i++)scanf("%s",&a[i]);
                                         ^
tracks.cpp:30:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
                        ^
tracks.cpp:31:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=0;i<n;i++)scanf("%s",&a[i]);
                                          ^

• Subtask 1: 30 / 30
• Subtask 2: 6.5625 / 70