Java | Leetcode Java题解之第456题132模式-题解：

class Solution {
    public boolean find132pattern(int[] nums) {
        int n = nums.length;
        List<Integer> candidateI = new ArrayList<Integer>();
        candidateI.add(nums[0]);
        List<Integer> candidateJ = new ArrayList<Integer>();
        candidateJ.add(nums[0]);

        for (int k = 1; k < n; ++k) {
            int idxI = binarySearchFirst(candidateI, nums[k]);
            int idxJ = binarySearchLast(candidateJ, nums[k]);
            if (idxI >= 0 && idxJ >= 0) {
                if (idxI <= idxJ) {
                    return true;
                }
            }
            
            if (nums[k] < candidateI.get(candidateI.size() - 1)) {
                candidateI.add(nums[k]);
                candidateJ.add(nums[k]);
            } else if (nums[k] > candidateJ.get(candidateJ.size() - 1)) {
                int lastI = candidateI.get(candidateI.size() - 1);
                while (!candidateJ.isEmpty() && nums[k] > candidateJ.get(candidateJ.size() - 1)) {
                    candidateI.remove(candidateI.size() - 1);
                    candidateJ.remove(candidateJ.size() - 1);
                }
                candidateI.add(lastI);
                candidateJ.add(nums[k]);
            }
        }

        return false;
    }

    public int binarySearchFirst(List<Integer> candidate, int target) {
        int low = 0, high = candidate.size() - 1;
        if (candidate.get(high) >= target) {
            return -1;
        }
        while (low < high) {
            int mid = (high - low) / 2 + low;
            int num = candidate.get(mid);
            if (num >= target) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return low;
    }

    public int binarySearchLast(List<Integer> candidate, int target) {
        int low = 0, high = candidate.size() - 1;
        if (candidate.get(low) <= target) {
            return -1;
        }
        while (low < high) {
            int mid = (high - low + 1) / 2 + low;
            int num = candidate.get(mid);
            if (num <= target) {
                high = mid - 1;
            } else {
                low = mid;
            }
        }
        return low;
    }
}