Implement Custom strcmp function

Code

#include <stdio.h>

int custom_strcmp(const char *a, const char *b) {
    // Your logic here
    int n1;
    int n2;
    for(n1=0;a[n1]!='\0';n1++);
    for(n2=0;b[n2]!='\0';n2++);
    if(n1>n2)
    return 100;
    if(n1==n2)
    {
        for(int i=0;i<n1;i++)
        {
            if(a[i]>b[i])
            return 1;
            else if(a[i]<b[i])
            return -1;
        }
        return 0;
    }
    else
    return -100;
}

int main() {
    char a[101], b[101];
    fgets(a, sizeof(a), stdin);
    fgets(b, sizeof(b), stdin);

    // Remove newline
    int i = 0;
    while (a[i]) {
        if (a[i] == '\n') { a[i] = '\0'; break; }
        i++;
    }
    i = 0;
    while (b[i]) {
        if (b[i] == '\n') { b[i] = '\0'; break; }
        i++;
    }

    printf("%d", custom_strcmp(a, b));
    return 0;
}

Solving Approach