Convert a String to Float

Code

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

float custom_atof(const char *str) {
    // Your logic here
    float num=0.00;
    int i=0;
    if (*(str+i)=='+' || *(str+i)=='-') i=1;
    while( *(str+i)!='.'){
        char ch=*(str+i);
        if (ch == '\0') break;
        num=(num*10)+ch-'0';
        i++;
    }
    if (*(str+i)!='\0') i++;
    float div_ten=10.0;
    while(*(str+i)!='\0'){
        char ch=*(str+i);
        num+=(ch-'0')/div_ten;
        div_ten*=10;
        i++;
    }
    if (*(str)=='-')    num*=(-1);
    return num;
}

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

 

 

 

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Input

123.45

Expected Output

123.45