数组

二分查找

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class Solution {
    public int search(int[] nums, int target) {
        int start = 0;
        int end = nums.length-1;
        int mid = 0;
        while(start<=end){
            mid = (start+end)/2;
            if(nums[mid]==target){
                return mid;
            }else if(nums[mid]>target){
                end = mid - 1;
            }else if(nums[mid]<target){
                start = mid + 1;
            }
        }
        return -1;
    }
}

移除元素

我是傻逼,从右往左找满足条件的

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class Solution {
public int removeElement(int[] nums, int val) {
    int left = 0;
    for(int i=0; i<nums.length; i++){
        if(nums[i]!=val){
            nums[left] = nums[i];
            left++;
        }
    }
    return left;
}
}