Submission #928989

#	Time	Username	Problem	Language	Result	Execution time	Memory
928989		Lyrically	Tracks in the Snow (BOI13_tracks)	C++17	0 / 100	468 ms	141912 KiB

tracks

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define pb push_back
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
void file(string s){
	freopen((s+".in").c_str(),"r",stdin);
	freopen((s+".out").c_str(),"w",stdout);
}
int n,m;
char c[4005][4005];
int dis[4005][4005];
int dx[4]={-1,0,1,0};
int dy[4]={0,-1,0,1};
signed main(){
	cin>>n>>m;
	rep1(i,n)scanf("%s",c[i]+1);
	memset(dis,-1,sizeof(dis));
	dis[1][1]=0;
	queue<array<int,2>> q;q.push({1,1});
	while(!q.empty()){
		array<int,2> x=q.front();q.pop();
		rep(i,4){
			int tx=x[0]+dx[i],ty=x[1]+dy[i];
			if(tx<1||ty<1||tx>n||ty>m)continue;
			if(c[tx][ty]=='.')continue;
			if(dis[tx][ty]!=-1)continue;
			dis[tx][ty]=dis[x[0]][x[1]]+(c[x[0]][x[1]]!=c[tx][ty]);
			q.push({tx,ty});
		}
	}
	cout<<dis[n][m]<<"\n";
	return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void file(std::string)':
tracks.cpp:9:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |  freopen((s+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:10:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |  freopen((s+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp: In function 'int main()':
tracks.cpp:19:16: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |  rep1(i,n)scanf("%s",c[i]+1);
      |           ~~~~~^~~~~~~~~~~~~

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