Convert a String to Float

Code

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

float custom_atof(const char *str) {
    
    // Method 1
    int i = 0;
    float result = 0.0;
    int sign = 1;
    float fraction = 0.0, divisor = 1.0;

    // Skip leading spaces
    while(str[i] == ' ') i++;

    // Handle sign
    if(str[i] == '-'){
        sign = -1;
        i++;
    }
    else if(str[i] == '+'){
        i++;
    }

    // Parse integer part
    while(str[i] >= '0' && str[i] <= '9'){
        result = result * 10.0 + (str[i] - '0');
        i++;
    }

    // Parse fractional part
    if(str[i] == '.'){
        i++;
        while(str[i] >= '0' && str[i] <= '9'){
            fraction = fraction * 10.0 + (str[i] - '0');
            divisor *= 10.0;
            i++;
        }
        result += fraction /divisor;
    }

    return sign * result;
}

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

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

    float value = custom_atof(str);
    printf("%.2f", value);
    return 0;
}

Solving Approach