20 lines
456 B
C++
20 lines
456 B
C++
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#include <bits/stdc++.h>
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using namespace std;
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const int N = 1e5 + 10;
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int q[N], hh, tt = -1;
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int main() {
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int n;
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cin >> n;
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while (n--) {
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string op;
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cin >> op;
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if (op == "push") cin >> q[++tt];
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else if (op == "empty")
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hh > tt ? cout << "YES" << endl : cout << "NO" << endl;
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else if (op == "query")
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cout << q[hh] << endl;
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else hh++;
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}
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return 0;
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}
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