Submission #436927

#	Time	Username	Problem	Language	Result	Execution time	Memory
436927		qwerasdfzxcl	Sandwich (JOI16_sandwich)	C++14	100 / 100	4100 ms	7872 KiB

sandwich

#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
char matrix[404][404];
int visited[404][404];
int dp[404][404], dx[4] = {-1, 1, 0, 0}, dy[4] = {0, 0, 1, -1}, n, m;

bool valid(int x, int y){
    return ((1<=x && x<=n) && (1<=y && y<=m));
}

int cnt;
bool dfs(int x, int y, int c){
    if (visited[x][y]) return visited[x][y]==1e9;
    visited[x][y] = c+1;
    cnt++;
    bool ret = 1;
    int nx1 = x+dx[c], nx2 = y+dy[c];
    if (valid(nx1, nx2)){
        ret &= dfs(nx1, nx2, c);
    }
    int d = 2;
    if (!c && matrix[x][y]=='Z') d = 3;
    if (c && matrix[x][y]=='N') d = 3;
    int nx3 = x+dx[d], nx4 = y+dy[d];
    if (valid(nx3, nx4)){
        if (d==2 && matrix[nx3][nx4]=='N') ret &= dfs(nx3, nx4, 0);
        else if (d==3 && matrix[nx3][nx4]=='Z') ret &= dfs(nx3, nx4, 0);
        else ret &= dfs(nx3, nx4, 1);
    }
    visited[x][y] = 1e9;
    return ret;
}

int main(){
    scanf("%d %d", &n, &m);
    for (int i=1;i<=n;i++){
        scanf("%s", matrix[i]+1);
        for (int j=1;j<=m;j++) dp[i][j] = 1e9;
    }
    for (int i=1;i<=n;i++){
        for (int i=1;i<=n;i++) fill(visited[i]+1, visited[i]+m+1, 0);
        cnt = 0;
        for (int j=1;j<=m;j++){
            cnt++;
            visited[i][j] = 1;
            if (matrix[i][j]=='N'){
                if (i+1<=n && !dfs(i+1, j, 1)) break;
                dp[i][j] = min(dp[i][j], cnt);
            }
            if (matrix[i][j]=='Z'){
                if (i-1>0 && !dfs(i-1, j, 0)) break;
                dp[i][j] = min(dp[i][j], cnt);
            }
            visited[i][j] = 1e9;
        }
    }
    for (int i=1;i<=n;i++){
        for (int i=1;i<=n;i++) fill(visited[i]+1, visited[i]+m+1, 0);
        cnt = 0;
        for (int j=m;j;j--){
            cnt++;
            visited[i][j] = 1;
            if (matrix[i][j]=='Z'){
                if (i+1<=n && !dfs(i+1, j, 1)) break;
                dp[i][j] = min(dp[i][j], cnt);
            }
            if (matrix[i][j]=='N'){
                if (i-1>0 && !dfs(i-1, j, 0)) break;
                dp[i][j] = min(dp[i][j], cnt);
            }
            visited[i][j] = 1e9;
        }
    }
    for (int i=1;i<=n;i++){
        for (int j=1;j<=m;j++){
            int ans = dp[i][j]<<1;
            if (ans==2e9) ans = -1;
            printf("%d ", ans);
        }
        printf("\n");
    }
    return 0;
}

Compilation message (stderr)

sandwich.cpp: In function 'int main()':
sandwich.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sandwich.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         scanf("%s", matrix[i]+1);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 35 / 35
• Subtask 2: 65 / 65