Convert a String to Float

Code

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

float custom_atof(const char *str) {
    int sign = 1;
    int i = 0;
    float sum = 0.0;

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

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

    while(str[i] >= '0' && str[i] <= '9') {
        sum = sum * 10 + (str[i] - '0');
        i++;
    }

    if(str[i] == '.') {
        i++;
        float divisor = 10.0;
        while(str[i] >= '0' && str[i] <= '9') {
            sum += (str[i] - '0') / divisor;
            divisor *= 10;
            i++;
        }
    }

    return sum * sign;
}


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