2015-2016 ACM-ICPC Complexity

题目地址：http://codeforces.com/gym/100819/attachments

题目：

Define the complexity of a string to be the number of distinct letters in it. For example, the stringstring has complexity 6 and the string letter has complexity 4.

You like strings which have complexity either 1 or 2. Your friend has given you a string andyou want to turn it into a string that you like. You have a magic eraser which will delete one letterfrom any string. Compute the minimum number of times you will need to use the eraser to turnthe string into a string with complexity at most 2.

Input

The input consists of a single line that contains a single string of at most 100 lowercase ASCIIletters (‘a’–‘z’).

Output

Print, on a single line, the minimum number of times you need to use the eraser.

思路：

没啥思路，水题。给你一堆字母，不管它有几种字母，要把它减少到只有两种，问最少删掉几个字母。

于是就用set统计个数，用数组记录每个字母的个数，贪心一下。

代码：

#include<iostream>
#include<string>
#include<cstring>
#include<set>
#include<algorithm>
using namespace std;
bool cmp(int a,int b)
{return a>b;
}
int main()
{string a;while(cin>>a){set<char>s;int b[150];memset(b,0,sizeof(b));int c=a.length();int i;for(i=0;i<c;i++){s.insert(a[i]);b[a[i]]++;}if(s.size()<=2)cout<<0<<endl;else{//int t=s.size()-2;sort(b,b+150,cmp);int sum=0;for(i=s.size();i>=2;i--){sum=sum+b[i];}cout<<sum<<endl;}}return 0;
}