LeetCode 75

Increasing Triplet Subsequence

Problem
LC 334
Topic
Array / String
File
official75_LC334IncreasingTripletSubsequence.java
Path
pkg5leetcode/official75/official75_LC334IncreasingTripletSubsequence.java
Package
pkg5leetcode.official75
Command
java pkg5leetcode/official75/official75_LC334IncreasingTripletSubsequence.java
Approach
Track smallest and second smallest seen so far.
Complexity
Time O(n), Space O(1)

LeetCode solutions

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pkg5leetcode/official75/official75_LC334IncreasingTripletSubsequence.java
1package pkg5leetcode.official75;2 3/*4 * Increasing Triplet Subsequence | LC 3345 * APPROACH: Track smallest and second smallest seen so far.6 * COMPLEXITY: Time O(n), Space O(1)7 */8public class official75_LC334IncreasingTripletSubsequence {9    static boolean increasingTriplet(int[] nums) {10        int first = Integer.MAX_VALUE, second = Integer.MAX_VALUE;11        for (int n : nums) {12            if (n <= first) first = n;13            else if (n <= second) second = n;14            else return true;15        }16        return false;17    }18 19    public static void main(String[] args) {20        check(increasingTriplet(new int[]{1,2,3,4,5}), "case1");21        check(!increasingTriplet(new int[]{5,4,3,2,1}), "case2");22        check(increasingTriplet(new int[]{2,1,5,0,4,6}), "case3");23        System.out.println("all tests passed");24    }25 26    static void check(boolean cond, String name) {27        if (!cond) throw new AssertionError("FAILED: " + name);28        System.out.println("  PASS " + name);29    }30}