Problem:
Score : 700 points

Problem Statement

There are some coins in the xy-plane.
The positions of the coins are represented by a grid of characters with H rows and W columns.
If the character at the i-th row and j-th column, s_{ij}, is #, there is one coin at point (i,j); if that character is ., there is no coin at point (i,j). There are no other coins in the xy-plane.

There is no coin at point (x,y) where 1\leq i\leq H,1\leq j\leq W does not hold.
There is also no coin at point (x,y) where x or y (or both) is not an integer.
Additionally, two or more coins never exist at the same point.

Find the number of triples of different coins that satisfy the following condition:

Choosing any two of the three coins would result in the same Manhattan distance between the points where they exist.

Here, the Manhattan distance between points (x,y) and (x',y') is |x-x'|+|y-y'|.
Two triples are considered the same if the only difference between them is the order of the coins.

Constraints

1 \leq H,W \leq 300

s_{ij} is # or ..

Input

Input is given from Standard Input in the following format:

H W
s_{11}...s_{1W}
:
s_{H1}...s_{HW}

Output

Print the number of triples that satisfy the condition.

Sample Input 1

5 4
#.##
.##.
#...
..##
...#

Sample Output 1

3

((1,1),(1,3),(2,2)),((1,1),(2,2),(3,1)) and ((1,3),(3,1),(4,4)) satisfy the condition.

Sample Input 2

13 27
......#.........#.......#..
#############...#.....###..
..............#####...##...
...#######......#...#######
...#.....#.....###...#...#.
...#######....#.#.#.#.###.#
..............#.#.#...#.#..
#############.#.#.#...###..
#...........#...#...#######
#..#######..#...#...#.....#
#..#.....#..#...#...#.###.#
#..#######..#...#...#.#.#.#
#..........##...#...#.#####

Sample Output 2

870

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int h = sc.nextInt();
        int w = sc.nextInt();
        int[][] map = new int[h+2000][w+2000];
        for(int i=0; i<h; i++){
            String s = sc.next();
            for(int j=0; j<w; j++){
                if(s.charAt(j) == '#'){
                    map[i+850][j+850] = 1;
                }
            }
        }
        sc.close();

        int[][] sum = new int[h+2000][w+2000];
        for(int i=-5; i<h+w+5; i++){
            int mi = 850 - w + i;
            int mj = 850;
            for(int j=-300; j<w+300; j++){
                int mi1 = mi + j;
                int mj1 = mj + j;
                sum[mi1][mj1] = sum[mi1-1][mj1-1];
                if(map[mi1][mj1] == 1){
                    sum[mi1][mj1]++;
                }
            }
        }

        long ans = 0;
        long ans2 = 0;
        for(int i=-5; i<h+w+5; i++){
            int mi = 850 - w + i;
            int mj = 850;
            for(int j=-5; j<w+5; j++){
                int mi1 = mi+j;
                int mj1 = mj+j;
                if(map[mi1][mj1] == 1){
                    for(int k=j+1; k<w+5; k++){
                        int mi2 = mi + k;
                        int mj2 = mj + k;
                        if(map[mi2][mj2] == 1){
                            int d = k-j;
                            ans += sum[mi2+d-1][mj2-d-1] - sum[mi1+d][mj1-d];
                            ans += sum[mi2-d-1][mj2+d-1] - sum[mi1-d][mj1+d];
                            ans2 += (map[mi2+d][mj2-d]) + (map[mi2-d][mj2+d]) + (map[mi1+d][mj1-d]) + (map[mi1-d][mj1+d]);
                            // for(int l=0; l<d+1; l++){
                            //     int mi3 = mi1 + d + l;
                            //     int mj3 = mj1 - d + l;
                            //     if(map[mi3][mj3]){
                            //         ans++;
                            //     }
                            //     mi3 = mi1 - d + l;
                            //     mj3 = mj1 + d + l;
                            //     if(map[mi3][mj3]){
                            //         ans++;
                            //     }
                            // }
                        }
                    }
                }
            }
        }
        for(int i=0; i<sum.length; i++){
            Arrays.fill(sum[i], 0);
        }

        for(int i=-5; i<h+w+5; i++){
            int mi = 850 - w + i;
            int mj = 850 + w;
            for(int j=-300; j<w+300; j++){
                int mi1 = mi + j;
                int mj1 = mj - j;
                sum[mi1][mj1] = sum[mi1-1][mj1+1];
                if(map[mi1][mj1] == 1){
                    sum[mi1][mj1]++;
                }
            }
        }

        for(int i=-5; i<h+w+5; i++){
            int mi = 850 - w + i;
            int mj = 850 + w;
            for(int j=-5; j<w+5; j++){
                int mi1 = mi+j;
                int mj1 = mj-j;
                if(map[mi1][mj1] == 1){
                    for(int k=j+1; k<w+5; k++){
                        int mi2 = mi + k;
                        int mj2 = mj - k;
                        if(map[mi2][mj2] == 1){
                            int d = k-j;
                            //if(d <= 1) continue;
                            ans += sum[mi2+d-1][mj2+d+1] - sum[mi1+d][mj1+d];
                            ans += sum[mi2-d-1][mj2-d+1] - sum[mi1-d][mj1-d];
                            ans2 += (map[mi2+d][mj2+d]) + (map[mi2-d][mj2-d]) + (map[mi1+d][mj1+d]) + (map[mi1-d][mj1-d]);
                            // for(int l=0; l<d+1; l++){
                            //     int mi3 = mi1 + d + l;
                            //     int mj3 = mj1 + d - l;
                            //     if(map[mi3][mj3]){
                            //         ans++;
                            //         if(mi1 == mi2 || mi2 == mi3 ||mi1 ==    mi3 || mj1 == mj2 || mj2 == mj3 | mj3  == mj1){
                            //             ans--;
                            //         }
                            //     }
                            //     mi3 = mi1 - d + l;
                            //     mj3 = mj1 - d - l;
                            //     if(map[mi3][mj3]){
                            //         ans++;
                            //         if(mi1 == mi2 || mi2 == mi3 ||mi1 ==    mi3 || mj1 == mj2 || mj2 == mj3 | mj3  == mj1){
                            //             ans--;
                            //         }
                            //     }
                            // }
                        }
                    }
                }
            }
        }
        System.out.println(ans + ans2/2);
    }
}