Codeforces Round #306 (Div. 2) A. Two Substrings string两个函数使用

C++ 中 string 的 find 函数 和 reverse 函数的使用

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
#include <vector>
#include <set>
#include <stack>
#include <map>
#include <climits>

using namespace std;

typedef long long ll;
const int maxn = 10000 + 7, INF = 0x3f3f3f3f, mod = 1e9 + 7;

string s;

int main() {

cin >> s;
int len = (int) s.size();
if(len < 4) return 0*puts("NO");

string t = s;
reverse(t.begin(), t.end()); // void

string t1 = "AB", t2 = "BA";

int p1 = s.find(t1), p2 = t.find(t1);
//cout << p1 << " == " << p2 << endl;
if( p1 >= 0 && p2 >= 0 && p1+p2+4 <= len) return 0*puts("YES");

p1 = s.find(t2), p2 = t.find(t2);
if( p1 >= 0 && p2 >= 0 && p1+p2+4 <= len) return 0*puts("YES");

return 0*puts("NO");
}