LintCode 练习题

import java.util.ArrayList;
        import java.util.List;


// This is the interface that allows for creating nested lists.
// You should not implement it, or speculate about its implementation

interface NestedInteger {

    // @return true if this NestedInteger holds a single integer,
    // rather than a nested list.
    public boolean isInteger();

    // @return the single integer that this NestedInteger holds,
    // if it holds a single integer
    // Return null if this NestedInteger holds a nested list
    public Integer getInteger();

    // @return the nested list that this NestedInteger holds,
    // if it holds a nested list
    // Return null if this NestedInteger holds a single integer
    public List<NestedInteger> getList();
}



public class Solution {

    private int partition(int[] array, int lo, int hi){
        //固定的切分方式
        int key =array[lo];
        while (lo<hi){
            while (array[hi]>=key&&hi>lo){
                hi--;
            }
            if(lo <hi){
                //交换
                int temp = array[lo];
                array[lo] = array[hi];
                array[hi] = temp;
                lo++;
            }
            while (array[lo]<=key&& hi>lo){
                lo++;
            }
            if(lo <hi){
                //交换
                int temp = array[lo];
                array[lo] = array[hi];
                array[hi] = temp;
                hi--;
            }
        }

        return hi;
    }

    public  void sort(int[] array,int lo, int hi){
        if(lo>=hi){
            return;
        }
        int index = partition(array,lo,hi);
        sort(array,lo,index-1);
        sort(array,index+1,hi);
    }

    /*
     * @param dictionary: an array of strings
     * @return: an arraylist of strings
     */
    public List<String> longestWords(String[] dictionary) {
        // write your code here
        List<String> words = new ArrayList<>();
        if(dictionary == null){
            return  null;
        }else {
            int len=0;
            for (int i=0;i < dictionary.length;i++){
                if(dictionary[i].length() >len){
                    words.clear();
                    words.add(dictionary[i]);
                    len = dictionary[i].length();
                    continue;
                }
                if(dictionary[i].length() == len){
                    words.add(dictionary[i]);
                }

            }
        }
        return words;
    }

    /**
     * 求数据中间值
     * @param nums
     * @return
     */
    public int median(int[] nums) {
        // write your code here
        int count = nums.length;
        if(count/2==0) {
            //偶数
            int target = nums[count/2];
            for(int i=0;i<count;i++){
                if(nums[i]<target){
                    target = nums[i];
                }

            }

        }else {
            //奇数
            for(int i=0;i<count;i++){

            }
        }
        return 0;

    }

    /**
     * @param nums: A list of integers
     * @return: A integer indicate the sum of max subarray
     */
    public int maxSubArray(int[] nums) {
        // write your code here
        int max=nums[0];
        for(int i=0;i<nums.length;i++)
        {
            if(max<nums[i])
                max=nums[i];
        }
        if(max<0)return max;
        int sum=0;
        max=0;
        for(int i=0;i<nums.length;i++)
        {
            sum+=nums[i];
            if(sum<0)sum=0; //子串为负 ，丢掉
            if(sum>max)
                max=sum;
        }
        return max;
    }

    // @return a list of integer
    // @param nestedList a list of NestedInteger
    public List<Integer> flatten(List<NestedInteger> nestedList) {
        // Write your code here
        List<Integer> list = new ArrayList<>();
        doflatten(nestedList,list);
        return list;
    }

    private void doflatten(List<NestedInteger> nestedList,List<Integer> list){
        if(nestedList != null){
            for(NestedInteger nested : nestedList){
                if(nested.isInteger()){
                    list.add(nested.getInteger());
                }else {
                    doflatten(nested.getList(),list);
                }
            }
        }
    }

}