Tontti

public class Tontti{
    
    
    public static void main(String[] args){
        IO io = new IO();
        
        int n = io.nextInt(), m = io.nextInt(), x = io.nextInt();
        
        String row;
        
        int[][] metaTrees = new int[n + 1][m + 1];
        
        for(int i = 0; i < n; i++){
            row = io.next();
            
            for(int j = 0; j < m; j++){
                
                metaTrees[i + 1][j + 1] = metaTrees[i][j + 1] + metaTrees[i + 1][j] - metaTrees[i][j];
                
                if(row.charAt(j) == '*')
                    metaTrees[i + 1][j + 1]++;
            }
        }
        
//        for(int i = 0; i < n; i++){
//            for(int j = 0; j < m; j++){
//                io.print(metaTrees[i + 1][j + 1] + " ");
//            }
//            io.println();
//        }
        
        
        int ans = 0, treeCount, max, min, k1, k2, minSize = (int)Math.ceil(Math.sqrt(x)) - 1;
        
        for(int i = 0; i + minSize < n; i++){
            
            
            for(int j = 0; j + minSize < m; j++){
                
                min = minSize;
                max = Math.min(n - i, m - j);
                
                do{
                    k1 = (max + min) / 2;
                    
                    treeCount = metaTrees[i + k1 + 1][j + k1 + 1]
                            - metaTrees[i + k1 + 1][j]
                            - metaTrees[i][j + k1 + 1]
                            + metaTrees[i][j];
                    
                    if(treeCount < x){
                        min = k1;
                    }else if(treeCount >= x){
                        max = k1;
                    }
                    
                }while(max - min > 1);
                
                k1 = min;
                
                min = k1;
                max = Math.min(n - i, m - j);
                
                do{
                    k2 = (max + min) / 2;
                    
                    treeCount = metaTrees[i + k2 + 1][j + k2 + 1]
                            - metaTrees[i + k2 + 1][j]
                            - metaTrees[i][j + k2 + 1]
                            + metaTrees[i][j];
                    
                    if(treeCount <= x){
                        min = k2;
                    }else if(treeCount > x){
                        max = k2;
                    }
                    
                }while(max - min > 1);
                
                ans += min - k1;
                
            }
        }
        
        io.println(ans);
        io.close();
    }
    
}

Test 1

Group: 1

Verdict: WRONG ANSWER

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: WRONG ANSWER

Test 4

Group: 1

Verdict: WRONG ANSWER

Test 5

Group: 1

Verdict: WRONG ANSWER

Test 6

Group: 2

Verdict: WRONG ANSWER

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED