最大矩形, 美团笔试题

Posted 2020-12-17 lixyuan

暴力直接解决， 输入处理较为麻烦。
LeetCode 85 一样。

import java.util.*;
public class Main {
    static int solve(int[][] arr, int n, int m) {
        int area = 0;
        for(int a = 0; a < n; a++){
            for(int b = 0; b < m; b++) {
                for(int c = 0; c <= a; c++){
                    for(int d = 0; d <= b; d++) {
                        int t = 0;
                        for(int i=c; i <= a; i++)
                            for(int j=d; j <= b; j++)
                                if(arr[i][j] == 1) t++;
                        if(t == (a-c+1)*(b-d+1))
                            area = Math.max(area, t);
                    }
                }
            }
        }
        return area;
    }
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        if(sc.hasNext()) sc.nextLine();
        List<String> list = new ArrayList<>();
        while(true){
            char[] s = sc.nextLine().toCharArray();
            StringBuilder sb = new StringBuilder();
            for(int i=0; i < s.length;i++)
                if(s[i] == ‘0‘ || s[i] == ‘1‘)
                    sb.append(s[i]);
            if(sb.length() == 0) break;
            list.add(sb.toString());
            if(s[s.length-1] != ‘,‘) break;
        }
        if(sc.hasNext()) sc.nextLine();
        int n = list.size(), m = list.get(0).length();
        int[][] a = new int[n][m];
        for(int i=0; i < n; i++)
            for(int j=0; j < m; j++)
                a[i][j] = list.get(i).charAt(j) == ‘1‘ ? 1 : 0;
        int area = solve(a, n, m);
 
        System.out.println(area);
    }
}