Yan-Ru Huang r1235613

## 修正的東西
//str_len

#include <stdio.h>
int strlen(char*s){
  int length=0;
  while(s[length])
    ++length;
  return length;
}
int main(){
	//str_len

	#include <stdio.h>
	int strlen(char*s){
	int length=0;
	while(s[length])
	++length;
	return length;
	}
	int main(){