44 lines
809 B
C++
44 lines
809 B
C++
#include <iostream>
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#include <vector>
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#include <stack>
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using namespace std;
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int main()
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{
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ios::sync_with_stdio(false);
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cin.tie(0);
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int n;
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cin >> n;
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vector<int> statu(n + 1);
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for (int i = 1; i <= n; i++){
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cin >> statu[i];
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}
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stack<int> sk;
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for (int i = 1; i <= n; i++){
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if (sk.empty()){
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sk.push(i);
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}
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else{
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// 状态一样就都留下，不一样就抵消删掉栈顶
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if (statu[i] == statu[sk.top()]){
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sk.push(i);
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}
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else{
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sk.pop();
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}
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}
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}
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int ans = -1;
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// 遍历栈，最后留存的就是最靠前的
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while (!sk.empty()){
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ans = sk.top();
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sk.pop();
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}
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cout << ans << endl;
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return 0;
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} |