1092 To Buy or Not to Buy (20 point(s))

Eva would like to make a string of beads with her favorite colors so she went to a small shop to buy some beads. There were many colorful strings of beads. However the owner of the shop would only sell the strings in whole pieces. Hence Eva must check whether a string in the shop contains all the beads she needs. She now comes to you for help: if the answer is Yes, please tell her the number of extra beads she has to buy; or if the answer is No, please tell her the number of beads missing from the string.

For the sake of simplicity, let's use the characters in the ranges [0-9], [a-z], and [A-Z] to represent the colors. For example, the 3rd string in Figure 1 is the one that Eva would like to make. Then the 1st string is okay since it contains all the necessary beads with 8 extra ones; yet the 2nd one is not since there is no black bead and one less red bead.

Figure 1

Input Specification:

Each input file contains one test case. Each case gives in two lines the strings of no more than 1000 beads which belong to the shop owner and Eva, respectively.

Output Specification:

For each test case, print your answer in one line. If the answer is Yes, then also output the number of extra beads Eva has to buy; or if the answer is No, then also output the number of beads missing from the string. There must be exactly 1 space between the answer and the number.

Sample Input 1:

ppRYYGrrYBR2258
YrR8RrY

Sample Output 1:

Yes 8

Sample Input 2:

ppRYYGrrYB225
YrR8RrY

Sample Output 2:

No 2

题目大意：给一串模式字符串，给一串目标字符，如果目标字符的每个字母都在模式串中出现（不考虑顺序），则输出Yes 并输出模式字符串与目标字符串长度的差值，否则输出No，并输出有几个目标串的字符没有在模式串中出现。

分析：用Hash数组对字符串标记计可。

code：

#include<bits/stdc++.h>
using namespace std;

int  Hash[1010];
int main(){
	string str,target;
	cin>>str>>target;
	int len1=str.length(),len2=target.length();
	for(int i=0;i<len1;i++)  Hash[str[i]]++;
	for(int i=0;i<len2;i++)  Hash[target[i]]--;
	int cnt=0;//少的个数 
	for(int i=0;i<len2;i++){
		if(Hash[target[i]]<0){
		//    cout<<Hash[target[i]]<<endl;
			cnt+=abs(Hash[target[i]]);
			Hash[target[i]]=0;//防止重复计数；
		}
	}
	//cout<<cnt<<endl;
	if(cnt==0){
		printf("Yes %d",len1-len2);
	}
	else printf("No %d",cnt);
	return 0;
}

暑假要开始继续刷题了。。。