蓝桥杯试题——子串分值

#include<iostream>
#include<string>
#include<cstring>

using namespace std;
int c[26];  //二十六个字母
string s;

int f(int m, int n)
{
	int a = 0;
	for (int i = m; i <= n; i++)
		c[s[i] - 'a']++;  //对应字母加加
	for (int i = 0; i < 26; i++)
		if (c[i] == 1) a++;  //字母只出现过一次的a++
	return a;

}

int main()
{
	int answer = 0;
	cin >> s;
	int len = s.length();
	for (int i = 0; i < len; i++)
		for (int j = i; j < len; j++) {
			answer += f(i, j);
			memset(c, 0, sizeof(int) * 26);  //重置零
		}
	cout << answer;
	return 0;
}