#include <stdlib.h>

int strSize(char* );
char* insert(char*, int, char*);

char* insert(char* target, int pos, char* str)
{
	int size = strSize(target) + strSize(str);
	char* temp = calloc(size , sizeof(char));

	for(int i = 0, j = 0; i < size; ++i)
	{
		if(i == pos)
		{
			for(; j < strSize(str); ++j)
			{
				temp[i+j] = str[j];
			}
		}
		temp[i+j] = target[i];
	}

	return temp;
}

int strSize(char* str)
{
	if(str == NULL) return 0;

	int i = 0;

	while(str[i])
	{
		++i;
	}
	return i;
}