Code for play fair cipher encryption

#include <bits/stdc++.h>
using namespace std;
#define SIZE 30

void toLowerCase(char plain[], int ps)
{
int i;
for (i = 0; i < ps; i++) {
if (plain[i] > 64 && plain[i] < 91)
plain[i] += 32;
}
}

int removeSpaces(char* plain, int ps)
{
...