# Maximum Width Ramp Problem

## Description

LeetCode Problem 962.

A ramp in an integer array nums is a pair (i, j) for which i < j and nums[i] <= nums[j]. The width of such a ramp is j - i.

Given an integer array nums, return the maximum width of a ramp in nums. If there is no ramp in nums, return 0.

Example 1:

``````1
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Input: nums = [6,0,8,2,1,5]
Output: 4
Explanation: The maximum width ramp is achieved at (i, j) = (1, 5): nums[1] = 0 and nums[5] = 5.
``````

Example 2:

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Input: nums = [9,8,1,0,1,9,4,0,4,1]
Output: 7
Explanation: The maximum width ramp is achieved at (i, j) = (2, 9): nums[2] = 1 and nums[9] = 1.
``````

Constraints:

• 2 <= nums.length <= 5 * 10^4
• 0 <= nums[i] <= 5 * 10^4

## Sample C++ Code

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class Solution {
public:
int maxWidthRamp(vector<int>& nums) {
if (nums.size() < 2)
return 0;
int ans = 0, n = nums.size()-1;
stack<int> st;
for (int j = 0; j < nums.size(); j++) {
if (st.empty() || nums[j] < nums[st.top()])
st.push(j);
}
for (int i = n; i > ans; i--) {
while (!st.empty() && nums[i] >= nums[st.top()]) {
ans = max(ans, i - st.top());
st.pop();
}
}
return ans;
}
};
``````