leetcode 503.下一个更大元素 II #栈

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503. 下一个更大元素 II

[webVueBlog]

503. 下一个更大元素 II

/*
 * @lc app=leetcode.cn id=503 lang=javascript
 *
 * [503] 下一个更大元素 II
 */

// @lc code=start
/**
 * @param {number[]} nums
 * @return {number[]}
 * 栈
[ 3, 2, 1, 4, 3, 2, 1, 4]
                          ?
[ 0, 1, 3, 7]
[ 4, 4, 4, -1]
[ 4, 4, 4, -1, -1, -1, -1, -1]
(80 ms)
 */
var nextGreaterElements = function(nums) {
    nums = nums.concat(nums);
    let len = nums.length;
    let oldLen = len / 2;
    let stack = [];
    let ans = new Array(oldLen).fill(-1);
    for (let i = 0; i < len; i++) {
        let current = nums[i]
        while (stack.length > 0 && current > nums[stack[stack.length - 1]]) {
            let topIndex = stack[stack.length - 1];
            ans[topIndex % oldLen] = current;
            stack.pop();
        }
        stack.push(i);
    }
    return ans;
};
// @lc code=end