Solution of that two questions

test.cpp

#include <iostream>
#include <iomanip>
#include <cstring>
#include <cstdlib>
#include <unordered_map>
using namespace std;

void findSomePair(int* arr, int arrSize, int sum, int* pairElementIndex1, int* pairElementIndex2);
void testFindSomePair();
void reverse(char* arr, int start, int end);
void reverseEachWord(char* arr);
void testReverseEachWord();


void findSomePair(int* arr, int arrSize, int sum, int* pairElementIndex1, int* pairElementIndex2) {

    if (arrSize <= 1) {
        *pairElementIndex1 = -1;
        *pairElementIndex2 = -1;
        return;
    }

    unordered_map<int, int> map;
    for (int i = 0; i < arrSize; ++i) {
        if (map.find(arr[i]) != map.end()) {
            *pairElementIndex1 = i;
            *pairElementIndex2 = map[arr[i]];
            return;
        } else {
            map[sum - arr[i]] = i;
        }
    }
    *pairElementIndex1 = -1;
    *pairElementIndex2 = -1;
}

void testFindSomePair() {
    int arr[] = {1, 4, 5, -1, 4, 7, 8, 8, 9, 12};
    int i1;
    int i2;
    findSomePair(arr, 10, 21, &i1, &i2);
    cout << arr[i1] << " " << arr[i2] << endl;
}

void reverse(char* arr, int start, int end) {
    char temp;
    while (start < end) {
        temp = arr[start];
        arr[start] = arr[end];
        arr[end] = temp;
        start++;
        end--;
    }
}

void reverseEachWord(char* arr) {
    int startInd = 0;
    int i = 0;
    while (true) {
        if (arr[i] == ' ') {
            reverse(arr, startInd, i - 1);
            startInd = i + 1;
        } else if (arr[i] == '\0') {
            reverse(arr, startInd, i - 1);
            break;
        }
        i++;
    }
}

void testReverseEachWord() {
    char str[] = "This is our country";
    reverseEachWord(str);
    cout << str << endl;
}


int main() {


    testFindSomePair();

    testReverseEachWord();


    return 0;
}