fuzzy_search.c

#include <stdio.h>
#include <string.h>

void substring(const char [], char[], int, int);

float fuzzy_string(const char*  a, const char*  b) {
    int reward = 0;
    int penalty = 0;
    int len_a = 0;
    while (a[len_a] != '\0') len_a++;
    int len_b = 0;
    char sub[64];
    while (b[len_b] != '\0') len_b++;
    for (int start = 0; start < len_a; start++) {
        for (int length = 0; length < len_a - 1; length++) {
            substring(a, sub, start, length);
            if(strstr(b, sub) != NULL) {
                reward += length * 2;
            } else {
                penalty += 1;
            }
        }
    }
    for (int start = 0; start < len_b; start++) {
        for (int length = 0; length < len_b - 1; length++) {
            substring(b, sub, start, length);
            if(strstr(a, sub) != NULL) {
                reward += length * 2;
            } else {
                penalty += 1;
            }
        }
    }
    float total = reward + penalty;
    return (float) reward / total;
}

void substring(const char s[], char sub[], int p, int l) {
   int c = 0;
   
   while (c < l) {
      sub[c] = s[p+c-1];
      c++;
   }
   sub[c] = '\0';
}

int main() {
    float x = fuzzy_string("andrew", "mandrew");
    printf("%f\n", x);
}