Hash Lookup

A tiny table can scan slots to find the value stored for a key.

hash_lookup.c

#include <stdio.h>

int main(void) {
    int target = ;
    int keys[4] = {3, 7, 11, 0};
    int values[4] = {30, 70, 110, 0};
    int found = -1;

    for (int i = 0; i < 4; i++) {
        if (keys[i] == target) {
            found = values[i];
        }
    }

    printf("found=%d\n", found);
    return 0;
}

#include <stdio.h>

int main(void) {
    int target = ;
    int keys[4] = {3, 7, 11, 0};
    int values[4] = {30, 70, 110, 0};
    int found = -1;

    for (int i = 0; i < 4; i++) {
        if (keys[i] == target) {
            found = values[i];
        }
    }

    printf("found=%d\n", found);
    return 0;
}

#include <stdio.h>

int main(void) {
    int target = ;
    int keys[4] = {3, 7, 11, 0};
    int values[4] = {30, 70, 110, 0};
    int found = -1;

    for (int i = 0; i < 4; i++) {
        if (keys[i] == target) {
            found = values[i];
        }
    }

    printf("found=%d\n", found);
    return 0;
}

key slot Each occupied slot stores a key and a matching value.

miss value The lookup keeps a fallback value when no slot contains the target key.