Tontti

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from sys import stdin

def readline():
    return stdin.readline().strip()

def get_vars():
    global n, m, x
    row1 = readline().split(' ')
    n = int(row1[0]) # Korkeus
    m = int(row1[1]) # Leveys
    x = int(row1[2]) # Tavoite
get_vars()

def isqrt(n):
    x = n
    y = (x + 1) // 2
    while y < x:
        x = y
        y = (x + n // x) // 2
    return x
    

def is_star(char):
    return char == '*'


def run():
    metsa = []
    for i in range(n):
        metsa.append(map(is_star, readline()))
        
    vaihtoehtoja = 0

    sqrt_x = isqrt(x) - 1
    
    for x1 in xrange(n-sqrt_x):
        next_x_bars = []
        for y1 in xrange(m):
            bar_height = y1+1
            bar = 0
            for x2 in xrange(x1, min(x1+bar_height, n)):
                if metsa[x2][y1]:
                    bar += 1
            next_x_bars.append(bar)
        
        next_y_bars = [0] * n
        for x2 in xrange(n-x1):
            bar_width = x2
            x2 = x1+x2
            bar = 0
            for y2 in xrange(min(bar_width, m)):
                if metsa[x2][y2]:
                    bar += 1
            next_y_bars[x2] = bar
        
        for y1 in xrange(m-sqrt_x):
            val = 0
            for w in xrange(1, min(n-x1+1, m-y1+1)):
                t_x2 = x1+w-1
                t_y2 = y1+w-1
                
                val += next_x_bars[t_y2]
                val += next_y_bars[t_x2]
                
                if val == x:
                    vaihtoehtoja += 1
                # Prepare for next
                if w != 1:
                    # For next_x_bars ->
                    if metsa[t_x2][t_y2]:
                        next_x_bars[t_y2] -= 1
                        # For next_y_bars -->
                        next_y_bars[t_x2] += 1
                    if metsa[t_x2][y1]:
                        next_y_bars[t_x2] -= 1
                    
    print(vaihtoehtoja)
run()

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED