93. 함수 포인터를 멤버로 가진 구조체 배열

1#include <stdio.h>
2 
3struct Op {
4    char sym;
5    int (*fn)(int, int);
6};
7 
8int add(int a, int b) { return a + b; }
9int sub(int a, int b) { return a - b; }
10int mul(int a, int b) { return a * b; }
11int mod(int a, int b) { return a % b; }
12 
13struct Op *find(struct Op *list, int n, char c) {
14    for (int i = 0; i < n; i++) {
15        if (list[i].sym == c) return &list[i];
16    }
17    return NULL;
18}
19 
20int main() {
21    struct Op table[4] = {{'+', add}, {'-', sub}, {'*', mul}, {'%', mod}};
22    char plan[] = "*%-+";
23    int v = 9;
24    for (int i = 0; plan[i] != '\0'; i++) {
25        struct Op *op = find(table, 4, plan[i]);
26        v = op->fn(v, i + 4);
27        printf("%c %d\n", op->sym, v);
28    }
29    table[0].fn = table[2].fn;
30    printf("%d\n", table[0].fn(3, 4) + find(table, 4, '-')->fn(10, 4));
31    return 0;
32}