문자반대출력/임다찬

~cpp
#include <stdio.h>
#include <string.h>
int datain(){
	char *a;
        FILE *input;
	input=fopen("source.txt","r");
	fgets(a,20,input);
        return *a;
}
void datasave(char *b){
	FILE *output;
	output=fopen("result.txt","w");
	fputs(b,output); 	
}             

int main(void){
	char *in,*out;

	*in=datain();   
	out=strrev(in);
        datasave(out);

	return 0;
}