Why doesn't if in an array work as it should?

Question

C++ / C#

Task: Given two arrays of the same size, get the third array, each element of which is equal to the maximum of the elements with the same number in the given arrays? (sorry for the text in printf)

#include <stdio.h>
#include <conio.h>
#include <locale.h>
#include <stdlib.h>
#include <time.h>

main()
{
  setlocale(LC_ALL,"RUS");
  int a[100],b[100],c[100];
  int i,n;
  
  printf("Vvedite razmer massiva: ");
  scanf("%d",&n);
  while(n<=1 || n>100)
  {
    printf("\nError! Povtorite : ");
    scanf("%d",&n);
  }
  for(i=0;i<n;i++)
  {
    a[i]=rand()%10;
    b[i]=rand()%15;
  }
  printf("\n1-massiv:\n ");
  for(i=0;i<n;i++)
  {
    printf("%d ",a[i]);
  }
  printf("\n2-massiv:\n ");
  for(i=0;i<n;i++)
  {
    printf("%d ",b[i]);  
  }
  printf("\nmassiv is max :\n ");
  for(i=0;i<n;i++)
  {
    if(a[i]=b[i])
    {
      c[i]=a[i];
    }
    else
    {
      if(a[i]>b[i])
      {
        c[i]=a[i];
      }
      else
      {
        c[i]=b[i];
      }
    }
  }
  for(i=0;i<n;i++)
  {
    printf("%d ",c[i]);
  }
  getch();
}

Answer 1

if(a[i]=b[i])
You either assign or compare