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// 2289. Steps to Make Array Non-decreasing
#include "leetcode.h"
/*
* given a 0-indexed integer array 'nums'. in one step, remofe all elements
* 'nums[i]' where 'nums[i - 1] > nums[i]' for all '0 < i < nums.size()'. return
* the number of steps performed until 'nums' becomes non-decreasing
*/
class Solution {
public:
int totalSteps(vector<int> &nums) {
int n = nums.size(), ans = 0;
vector<int> stack, dp(n);
for (int i = n - 1; i >= 0; --i) {
while (!stack.empty() && nums[i] > nums[stack.back()]) {
dp[i] = max(++dp[i], dp[stack.back()]);
stack.pop_back();
ans = max(ans, dp[i]);
}
stack.push_back(i);
}
return ans;
}
};
int main() {
Solution obj;
vector<int> n1 = {5, 3, 4, 4, 7, 3, 6, 11, 8, 5, 11}, n2 = {4, 5, 7, 7, 13};
printf("%d\n", obj.totalSteps(n1)); // expect: 3
printf("%d\n", obj.totalSteps(n2)); // expect: 0
}
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