Forum Debian Users Gang

#include <stdio.h>
#define MAX 100
#define DOT '.'

char *add(char *x, char *y);

int main() {
    char x[MAX], y[MAX], *s;
    printf("podaj pierwsza: ");
    scanf("%s", x);
    printf("podaj druga: ");
    scanf("%s", y);
    
    s = add(x, y);
    if (s != NULL) {
        printf(" %sn %snn%snn", x, y, s);
        free(s);
    }
    return 0;
}

char *add(char *x, char *y) {
    int dot1, dot2, len, dot, i;
    char *c;
    c = strchr(x, DOT);
    if (c == NULL)
        return NULL;
    dot1 = strlen(x) - strlen(c);
    c = strchr(y, DOT);
    if (c == NULL)
        return NULL;
    dot2 = strlen(y) - strlen(c);

    if (dot1 > dot2) 
        len = dot1;
    else 
        len = dot2;

    dot = len;
    
    if (strlen(x) - dot1 > strlen(y) - dot2)
        len += strlen(x) - dot1;
    else
        len += strlen(y) - dot2;
   
    char a[len + 1], b[len + 1], *s;
    s = (char *)malloc((len + 2) * sizeof(char));
    if (s == NULL) {
        fprintf(stderr, "nie zaalokowalem!n");
        exit(1);
    }
    
    for (i = 0; i < len; i++) {
        a[i] = '0';
        b[i] = '0';
        s[i] = '0';
    }
    a[len] = '';
    b[len] = '';
    s[len] = '0';
    s[len + 1] = '';
    
    int k = 0, l = 0;
    for (i = 0; i < len; i++) {
        if ((i + dot1 >= dot) && (k < strlen(x))) {
            a[i] = x[k];
            k++;
        }
        if ((i + dot2 >= dot) && (l < strlen(y))) {
            b[i] = y[l];
            l++;
        }
    }
    
    int carry = 0;
    char q;
    for (i = len - 1; i >= 0; i--) {
        if (i == dot) {
            s[i + 1] = DOT;
            continue;
        }

        q = a[i] + b[i] - '0' + carry;
        if (q > '9') {
            carry = 1;
            q -= 10;
        }
        s[i + 1] = q;
        
    }
    if (carry != 0)
        s[0] = '1';
    
    return s;
}