模拟栈
比较容易知道碰到ooO出栈2个,OO出栈,但是涉及正序输出,普通的stack搞不定,可以用deque,或者手写个数组。
#pragma GCC target("avx,sse2,sse3,sse4,popcnt")
#pragma GCC optimize("O2,O3,Ofast,inline,unroll-all-loops,-ffast-math")
#include <bits/stdc++.h>
using namespace std;
#define js ios::sync_with_stdio(false);cin.tie(0); cout.tie(0)
typedef long long ll; typedef unsigned long long ull; typedef long double ld;
const ll MOD = 1e9 + 7;
inline ll read() { ll s = 0, w = 1; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) if (ch == '-') w = -1; for (; isdigit(ch); ch = getchar())    s = (s << 1) + (s << 3) + (ch ^ 48); return s * w; }
inline void write(ll x) { if (!x) { putchar('0'); return; } char F[40]; ll tmp = x > 0 ? x : -x; if (x < 0)putchar('-');    int cnt = 0;    while (tmp > 0) { F[cnt++] = tmp % 10 + '0';        tmp /= 10; }    while (cnt > 0)putchar(F[--cnt]); }
inline ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
ll qpow(ll a, ll b) { ll ans = 1;    while (b) { if (b & 1)    ans *= a;        b >>= 1;        a *= a; }    return ans; }    ll qpow(ll a, ll b, ll mod) { ll ans = 1; while (b) { if (b & 1)(ans *= a) %= mod; b >>= 1; (a *= a) %= mod; }return ans % mod; }
inline int lowbit(int x) { return x & (-x); }
string s;
deque<char> q;
int main() {
    js;
    while (cin >> s) {
        for (auto i : s) {
            if (q.empty() or q.back() != i)    q.push_back(i);
            else {
                if (i == 'o') {
                    q.pop_back();
                    if (!q.empty() and q.back() == 'O')    q.pop_back();
                    else q.push_back('O');
                }
                else q.pop_back();
            }
        }
        while (q.size()) {
            cout << q.front();
            q.pop_front();
        }
        cout << '\n';
    }
    return 0;
}
 
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京公网安备 11010502036488号