Submission #67039

#	Time	Username	Problem	Language	Result	Execution time	Memory
67039		RezwanArefin01	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	958 ms	297244 KiB

tracks

///usr/bin/g++ -O2 $0 -o ${0%.cpp} && echo "----------" && ./${0%.cpp}; exit;
#include <bits/stdc++.h>
using namespace std;

typedef long long ll; 
typedef pair<int, int> ii; 

const int N = 4010; 

char g[N][N]; 
int dx[] = {0, 0, 1, -1}; 
int dy[] = {1, -1, 0, 0}; 
int d[N][N], n, m; 

int main() {
    scanf("%d %d", &n, &m);
    for(int i = 0; i < n; i++) 
        scanf(" %s", g[i]); 

    deque<ii> q; 
    memset(d, 63, sizeof d); 
    q.push_back({0, 0}); 
    d[0][0] = 1 ;
    while(!q.empty()) {
        ii u = q.front(); q.pop_front(); 
        int x = u.first, y = u.second;
        for(int i = 0; i < 4; i++) {
            int xx = x + dx[i], yy = y + dy[i]; 
            if(xx >= 0 && xx < n && yy >= 0 && yy < m && g[xx][yy] != '.') {
                int c = g[x][y] != g[xx][yy];
                if(d[xx][yy] > d[x][y] + c) {
                    d[xx][yy] = d[x][y] + c;
                    if(c) q.push_back({xx, yy}); 
                    else q.push_front({xx, yy}); 
                }
            }
        }
    }
    int mx = 0; 
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) if(g[i][j] != '.') {
            mx = max(mx, d[i][j]); 
        }
    }
    printf("%d\n", mx); 
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
tracks.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf(" %s", g[i]); 
         ~~~~~^~~~~~~~~~~~~

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