Calculating the maximum number of an array by divide and conquer algorithm

Question

I made a program that calculates the maximum value of an array using the divide and conquer algorithm, but the output is 0.

#include <iostream>
using namespace std;
int array[50];

void maximum(int index1, int index2, int&max_number) {
    int max_number1;
    int max_number2;
    int half;
    if (index1 == index2)
        max_number = array[index1];
    else {
        half = (index1 + index2) / 2;
        maximum(index1, half, max_number1);
        maximum(half + 1, index2, max_number2);
        if(max_number1 < max_number2)
        max_number = max_number2;
        else
        max_number = max_number1;
    }
}

int main() {
    int index1;
    int index2;
    int max_number = 0;
    cout << "index2 = ";
    cin >> index2;
    for (index1 = 0; index1 < index2; index1++)
        cin >> array[index1];
        maximum(index1, index2, max_number);
    cout << "maximum number = " << max_number;
    return 0;
}

What should I do?

Answer 1

you have a typo in this part of code

for(index1 = 0; index1 < index2; index1++)

index1 will increased till to index2, and then

maximum(index1, index2, max_number);

will pass the same the same values in the 1st/2nd parameter, you may change the code like as

for(index1 = 0; index1 < index2; index1++)
    cin>>array[index1];
index1 = 0;
maximum(index1, index2, max_number);