Programming

#include <iostream>
#include <algorithm>
#include <cstring>
#include <deque>
#include <iterator>

using namespace std;

int main() {
    char str[] = "Hello";
    char srch[] = "World";
    char merg[strlen(str) + strlen(srch) + 1];
    std::deque<char> d(20);
    std::merge(&str[0], &str[strlen(str)], &srch[0], &srch[strlen(srch)], &merg[0]);
    std::merge(&str[0], &str[strlen(str)], &srch[0], &srch[strlen(srch)], d.begin());
    cout << merg << endl;
    std::copy(d.begin(), d.end(), ostream_iterator<char>(std::cout, ""));
    cout << endl;
}

HWelloorld
HWelloorld

#include <string.h>
#include <stdio.h>

int main(void)
{
    char str[] = "Hello";
    char srch[] = "World";
    char output[512];

    output[0]='\0';
    strcat(output, str);
    strcat(output, srch);
    printf("output is %s\n", output);
}