UIT 8.08

#include <iostream>
#include <string.h>
using namespace std;
#define MAX 300

int myStrlen(char s[], int k);
void myStrcpy(char s[], int vt, char s1[], int k);
void mySubstr(char s[], int b, int count, char ss[]);
bool myStrcat(char s1[], char s2[]);
void ChenChuoiTaiVitriK(char s[], char s1[], int k);

int main()
{
    //freopen("input.txt","r",stdin);
    char s[MAX], s1[MAX];
    gets(s);
    gets(s1);
    int k;
    cin >> k;
    if (k < 0 || k>myStrlen(s, 0))
        cout << "Vi tri " << k << " khong thoa dieu kien." << endl;
    else
    {
        ChenChuoiTaiVitriK(s, s1, k);
        cout << s;
    }
}

int myStrlen(char s[], int k){
    int len = 0;
    while (s[len]!='\0') len++;
    return len;
}

void ChenChuoiTaiVitriK(char s[], char s1[], int k){
    int len = 0, len1 = 0;
    char tmp[MAX];
    for(int i=0; i<k; i++) tmp[i] = s[i];
    len = k;
    for(int i=0; s1[i]!='\0'; i++) tmp[len++] = s1[i];
    tmp[len++] = ' ';
    for(int i=k; s[i]!='\0'; i++) tmp[len++] = s[i];
    for(int i=0; tmp[i]!='\0'; i++) s[i] = tmp[i];
}