Given two strings S1and S2, S = S1- S2is defined to be the remaining string after taking all the characters in S2from S1. Your task is simply to calculate S1- S2for any given strings. However, it might not be that simple to do itfast.
Input Specification:
Each input file contains one test case. Each case consists of two lines which gives S1and S2, respectively. The string lengths of both strings are no more than 104. It is guaranteed that all the characters are visible ASCII codes and white space, and a new line character signals the end of a string.
Output Specification:
For each test case, print S1- S2in one line.
strlen（）本身就是一个循环，所以不要在循环中使用，超时了
#include <stdio.h>#include <stdlib.h>#include <string.h>#define N 10001int main (){char str1[N],str2[N];bool flag[92];memset(flag,0,sizeof(flag));gets(str1);gets(str2);int i,length;length=strlen(str2);for( i=0;i<length;i++){flag[str2[i]-' ']=true;}length=strlen(str1);for( i=0;i<length;i++){if( flag[str1[i]-' ']!=true) printf("%c",str1[i]);}printf("\n");system("pause");return 0;}
，成功是什么?就是走过了所有通向失败的路，
