Shining Problem Part-2

///Shining Problem Part-2
#include<stdio.h>

void reverseStr(char str1[100], char str2[100],int n )
{
    int i, j, len;
    for (i = 0; str1[i] != '\0'; i++);

    len = i - 1;

    for (i = n-1, j = 0; i>=0; i--, j++)
    {
        str2[j] = str1[i];
    }
    str2[j] = '\0';

}
int main()
{
    int n;
    char s1[100], s2[100];
    printf("Enter a string: \n");
    gets(s1);
    printf("How much number are you willing to take : ");
    scanf("%d", &n);
    reverseStr(s1, s2,n);
    printf("String After Reversing: %s\n", s2);

}