Decimal to binary in C++

#include <iostream>
#include <string.h>

using namespace std;

int main() {
    unsigned int n;
    char num[200]="";
    cout << "Enter a positive decimal number: ";
    cin >> n;
    while(n>0) {
        if(n%2==0)
            strcpy(num,strcat(num,"0"));
        else
            strcpy(num,strcat(num,"1"));
        n=n/2;
    }
    int len=strlen(num);
    while(len>0) {
        cout << num[len-1];
        len--;
    }
    cout << endl;
    return 0;
}