Splicing strings with custom functions

adopt for Loop through the string , Add the latter string to the space of the previous string , Last string before final output , Realize string splicing

#include<bits/stdc++.h> 
#include<string.h>

using namespace std;

int main( )
{
	char m[20],n[20];
	int a,b,c;
	scanf("%s",&m);
	scanf("%s",&n);
	a = strlen(m);
	b = strlen(n);
	for(int i=0;i<b;i++)
	{
		m[a+i]=n[i];
	}
	for(int j=0;j<(a+b);j++) 
	{
		printf("%c",m[j]);
	}
    return 0;
}