uva 10579 - Fibonacci Numbers

#include <stdio.h>
#include <string.h>

char fibo[5000][1001];

void build_fibo_string()
{
    int i, j;
    for(i = 0; i < 5000; i++){
        for(j = 0; j < 1000; j++){
            fibo[i][j] = '0';
        }
        fibo[i][1000] = '\0';
    }
}

void create_fibo_number(int n)
{
    int sum = 0, carry = 0;
    int i;
    for(i = 999; i >= 0; i--){
        sum = fibo[n-1][i] + fibo[n-2][i] + carry - '0' - '0';
        carry = (sum) / 10;
        fibo[n][i] = (sum) % 10 + '0';
    }
}

void build_fibo_number()
{
    int i, j;
    fibo[0][999] = '1';
    fibo[1][999] = '1';
    for(i = 2; i < 5000; i++){
        create_fibo_number(i);
        if(fibo[i][0] > '0') break;
    }
}

int main()
{
    int n, i, j;

    build_fibo_string();
    build_fibo_number();

    while(scanf("%d", &n) == 1){
        i = 0;
        //printf("HI\n");
        for(i = 0; ; i++){
            //printf("HELLO\n");
            if(fibo[n - 1][i] != '0'){
                for(j = i; j < 1000; j++){
                    printf("%c", fibo[n - 1][j]);
                }
                printf("\n");
                break;
            }
        }
    }


    return 0;
}