#include <bits/stdc++.h>
using namespace std;

// Prepare >  C++ > Introduction: Pointer

ostream& operator<<(ostream& os, const pair<int,int>& p)
{
    return os << "(" << p.first << "," << p.second << ")";
}

void update(int *a,int *b) {
    // Modify the values in memory so that a contains their sum 
    // and b contains their absoluted dfference.
    int c = *a;
    int d = *b;
    *a = c + d;
    *b = abs(c-d);
}

int main() {

    vector<tuple<pair<int,int>,pair<int,int>>> testCases = {
        {{4,5}, {9,1} },
        {{0,7}, {7,7} },
    };

    for (auto& tc: testCases)
    {    
        int a = get<0>(tc).first, b = get<0>(tc).second;
        int *pa = &a, *pb = &b;
        update(pa, pb);
        
        pair<int,int> result = {a,b};
        pair<int,int> expected =get<1>(tc);
        
        int width = 10;
        cout << setw(width) << "input: " << get<0>(tc) << endl;
        cout << setw(width) << "result: " << result << endl;        
        cout << setw(width) << "expected: " << expected << endl;        
        cout << (result == expected ? "\033[32mpassed\033[0m" : "\033[31mfailed\033[0m") << endl;
        cout << "----------------------------\n";
    }
    
    return 0;
}