27 lines
557 B
C++
27 lines
557 B
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 100010;
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int stk[N], tt;
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int main() {
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string op;
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int n;
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cin >> n;
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while (n--) {
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cin >> op;
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if (op == "push") {
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int x;
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cin >> x;
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stk[++tt] = x;
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} else if (op == "pop")
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tt--;
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else if (op == "query")
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printf("%d\n", stk[tt]);
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else if (op == "empty") {
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if (tt == 0) printf("YES\n");
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else printf("NO\n");
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}
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}
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return 0;
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} |