字符串转换为数字

#include "stdafx.h"#include <string>#include <sstream>using namespace std; int _tmain(int argc, _TCHAR* argv[]){char s[80];    fputs(fgets(s, 80, stdin), stdout);fprintf(stdout,"%s",s);//int b;//sscanf(s,"%d", &b);istringstream si("55");si>>b;printf("ss%d",b);return 0;}