for.cpp

            for (int a = 1; a < 999; a++) {
                for (int b = 1; b + a < 1000; b++) {
                    for (int c = 1; c+b+a < 1001; c++) {
                        if (a * a + b * b == c * c) {
                            p[a + b + c]++;
                        }
                    }                    
                }                
            }