Thread: Project Euler Problem 8

I'm having a bit of trouble solving this problem. The objective is to find the largest product of five consecutive digits in this 1,000 digit number.

Code:

#include <stdio.h>

int main(void)
{
	char *num = "73167176531330624919225119674426574742355349194934"
"96983520312774506326239578318016984801869478851843"
"85861560789112949495459501737958331952853208805511"
"12540698747158523863050715693290963295227443043557"
"66896648950445244523161731856403098711121722383113"
"62229893423380308135336276614282806444486645238749"
"30358907296290491560440772390713810515859307960866"
"70172427121883998797908792274921901699720888093776"
"65727333001053367881220235421809751254540594752243"
"52584907711670556013604839586446706324415722155397"
"53697817977846174064955149290862569321978468622482"
"83972241375657056057490261407972968652414535100474"
"82166370484403199890008895243450658541227588666881"
"16427171479924442928230863465674813919123162824586"
"17866458359124566529476545682848912883142607690042"
"24219022671055626321111109370544217506941658960408"
"07198403850962455444362981230987879927244284909188"
"84580156166097919133875499200524063689912560717606"
"05886116467109405077541002256983155200055935729725"
"71636269561882670428252483600823257530420752963450";


	int i, tmp=1, product = 0, final_product = 0;


	for(i = 0; num[i] != NULL; i++)
	{
		printf("%i\n", num[i] - '0');

		tmp *= num[i] - '0';

		if((i+1) % 5 == 0)
		{
			printf("------------------------\n");
			product = tmp;

			tmp = 1;

			if(product > final_product)
				final_product = product;
		}

	}

	printf("Largest product ------> %i\n", final_product);

	return 0;
}

The answer should be 40,824 but I'm getting 31,752. Any ideas where I'm going wrong?