#include <iostream>
using namespace std;

int addInt(int n, int m){
    return n + m;
}

int timeInt(int n, int m){
    return n * m;
}

int main(){
/************** function pointer *****************/
    int sum = 0;

    // declare
    int (*functionPtr)(int,int);

    // read values
    // 1. assign memory address of a function to the pointer
    functionPtr = addInt; //  或這樣寫: functionPtr = &addInt;

    // compute
    sum = functionPtr(2,3); // 2 + 3 = 5 //  或這樣寫: sum = (*functionPtr)(2,3);

    // show result
    printf("%d\n",sum);

    // read values
    // 2. assign memory address of another function
    functionPtr = timeInt;
    // compute
    sum = functionPtr(2,3); // 2 * 3 = 6
    // show result
    printf("%d\n",sum);

    return 0;
}