Convert String to Integer

Code

#include <stdio.h>
#include <stdint.h>

int custom_atoi(const char *str) {
  int i=0,num,r=0,sign=1;
  if(str[i]=='-'){sign=-1;i++;}
  if(str[i]=='+'){sign=1;i++;}
  while(str[i]>='0' && str[i]<='9')
    {    num=str[i]-'0';
        r=r*10+num;
        i++;
    }

  
   int ans=r*sign;
    return ans;
}

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

    // Remove newline
    uint8_t i = 0;
    while (str[i]) {
        if (str[i] == ' ') {
            str[i] = '\0';
            break;
        }
        i++;
    }

    printf("%d", custom_atoi(str));
    return 0;
}

Solving Approach