25算法设计4.2 山峰

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#include <iostream> #include <algorithm> #include <vector> using namespace std; const int N = 1010; int n; vector<int> nums; int main() { cin >> n; nums.resize(n); for (int i = 0; i < n; i ++ ) cin >> nums[i]; nums.erase(unique(nums.begin(), nums.end()), nums.end()); if (nums.size() <= 2) cout << nums.size() << endl; int res = 2; for (int i = 1; i + 1 < nums.size(); i ++ ) { int a = nums[i - 1], b = nums[i], c = nums[i + 1]; if ((b > a && b > c) || (b < a && b < c)) res ++; } cout << res << endl; return 0; }