LeetCode-0707

300. 最长递增子序列(中等)

//	二分法
class Solution {
    public int lengthOfLIS(int[] nums) {
        int n = nums.length;

        int res[] = new int[n];
        int it = 0;

        for(int num:nums){
            int index = lower_bound(res,num,it);
            if(index==it){
                res[it++] = num;
            }else{
                res[index] = num;
            }
        }
        return it;
    }


    public int lower_bound(int res[],int v,int it){

        int left = 0;
        int right = it;
        while(left<right){
            int mid = left+(right-left)/2;
            if(res[mid] < v ){
                left = mid+1;
            }else {
                right = mid;
            }
        }
        return left;
    }
}

//  dp法： if(nums[i]>nums[j])dp[i]=dp[j]+1
class Solution {
    public int lengthOfLIS(int[] nums) {

        int n = nums.length;
        int dp[] = new int[n];
        int max = 1;
        Arrays.fill(dp,1);

        for(int i=1;i<n;i++){
            for(int j=i-1;j>=0;j--)
                if(nums[j]<nums[i])
                    dp[i] = Math.max(dp[i],dp[j]+1);
            if(dp[i]>max)max = dp[i];
        }
        return max;
    }
}

674. 最长连续递增序列(简单)

class Solution {
    public int findLengthOfLCIS(int[] nums) {

        int n = nums.length;
        int dp[] = new int[n];
        Arrays.fill(dp,1);

        int max = 1;

        for(int i=1;i<n;i++){
            if(nums[i]>nums[i-1])dp[i]=dp[i-1]+1;
            if(dp[i]>max)max = dp[i];
        }
        return max;
    }
}

718. 最长重复子数组（中等）

class Solution {
    public int findLength(int[] nums1, int[] nums2) {

        int n = nums1.length;
        int m = nums2.length;
        int max = 0;

        int dp[][] = new int[n+1][m+1];

        for(int i=1;i<=n;i++){
            for(int j=1;j<= m;j++){
                if(nums1[i-1]==nums2[j-1]){
                    dp[i][j] = dp[i-1][j-1]+1;
                }
                max = Math.max(max,dp[i][j]);
            }
        }
        return max;
    }
}

1143. 最长公共子序列(中等)

class Solution {
    public int longestCommonSubsequence(String text1, String text2) {
        
        int n = text1.length();
        int m = text2.length();
        
        int dp[][] = new int[n+1][m+1];

        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                if(text1.charAt(i-1)==text2.charAt(j-1)){
                    dp[i][j] = dp[i-1][j-1]+1;
                }else{
                    dp[i][j] = Math.max(Math.max(dp[i-1][j-1],dp[i-1][j]),dp[i][j-1]);
                }
            }
        }
        return dp[n][m];
    }
}

文章来源地址https://uudwc.com/A/XNG85