markilue
/
self_example
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

leecode，rt_phm更新更新

This commit is contained in:
kevinding1125 2023-05-31 13:37:50 +08:00
parent 597ed80123
commit 220ffec10d
6 changed files with 296 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/dynamic/LC_309_MaxProfit.java Normal file
View File

@ -0,0 +1,16 @@
package com.markilue.leecode.hot100.interviewHot.dynamic;
/**
*@BelongsProject: Leecode
*@BelongsPackage: com.markilue.leecode.hot100.interviewHot.dynamic
*@Author: markilue
*@CreateTime: 2023-05-31 13:23
*@Description: TODO 力扣309 最佳买卖股票时机含冷冻期
*@Version: 1.0
*/
public class LC_309_MaxProfit {
public int maxProfit(int[] prices) {
return 0;
}
}

102
Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/union_find/second/LC_685_FindRedundantConnection.java Normal file
View File

@ -0,0 +1,102 @@
package com.markilue.leecode.hot100.interviewHot.union_find.second;
import java.util.ArrayList;
/**
*@BelongsProject: Leecode
*@BelongsPackage: com.markilue.leecode.hot100.interviewHot.union_find.second
*@Author: markilue
*@CreateTime: 2023-05-31 10:47
*@Description: TODO 力扣685 冗余连接II
*@Version: 1.0
*/
public class LC_685_FindRedundantConnection {
int[] father;//父节点
int n;//父节点个数
private void init(int[] father) {
for (int i = 0; i < father.length; i++) {
father[i] = i;
}
}
private int find(int u) {
if (u == father[u]) {
return u;
}
father[u] = find(father[u]);
return father[u];
}
private void join(int u, int v) {
u = find(u);
v = find(v);
if (u == v) return;
father[v] = u;
}
private boolean same(int u, int v) {
u = find(u);
v = find(v);
return u == v;
}
private boolean isSameAfterRemove(int[][] edges, int delete) {
init(father);
for (int i = 0; i < edges.length; i++) {
if (i == delete) {
continue;
}
if (same(edges[i][0], edges[i][1])) {
return false;
}
join(edges[i][0], edges[i][1]);
}
return true;
}
private int[] removeOne(int[][] edges) {
init(father);
for (int i = 0; i < edges.length; i++) {
if (same(edges[i][0], edges[i][1])) {
return edges[i];
}
join(edges[i][0], edges[i][1]);
}
return null;
}
public int[] findRedundantDirectedConnection(int[][] edges) {
n = 1010;
father = new int[n];
//计算每个节点的入度
int[] inDegree = new int[n];
for (int[] edge : edges) {
inDegree[edge[1]]++;
}
ArrayList<Integer> twoDegree = new ArrayList<>();
//判断入度为2的节点，该节点一定有子节点需要删除;反向遍历,因为后面的删除优先级更高
for (int i = edges.length-1; i >=0; i--) {
if (inDegree[edges[i][1]] == 2) {
twoDegree.add(i);//这个节点需要删除
}
}
if (!twoDegree.isEmpty()) {
if (isSameAfterRemove(edges, twoDegree.get(0))) {
return edges[twoDegree.get(0)];
}
return edges[twoDegree.get(1)];
}
return removeOne(edges);
}
}

3
Leecode/src/main/java/com/markilue/leecode/hot100/second/T77_297_Codec.java
View File

@ -60,6 +60,7 @@ public class T77_297_Codec {
// Decodes your encoded data to tree.
public TreeNode deserialize(String data) {
if (in >= data.length() || data.charAt(in) == ')') {
return null;
}
@ -70,7 +71,7 @@ public class T77_297_Codec {
in++;
}
while (in < data.length() && data.charAt(in) >= '0' && data.charAt(in) <= '9') {
while (in < data.length() && Character.isDigit(data.charAt(in))) {
root.val = root.val * 10 + data.charAt(in)-'0';
in++;
}

50
Leecode/src/main/java/com/markilue/leecode/hot100/second/T78_300_LengthOfLIS.java Normal file
View File

@ -0,0 +1,50 @@
package com.markilue.leecode.hot100.second;
import org.junit.Test;
import java.util.ArrayDeque;
/**
*@BelongsProject: Leecode
*@BelongsPackage: com.markilue.leecode.hot100.second
*@Author: markilue
*@CreateTime: 2023-05-31 11:18
*@Description: TODO 力扣300 最长递增子序列
*@Version: 1.0
*/
public class T78_300_LengthOfLIS {
@Test
public void test() {
// int[] nums ={10,9,2,5,3,7,101,18};
int[] nums = {0, 1, 0, 3, 2, 3};
System.out.println(lengthOfLIS(nums));
}
//构造一个单调栈:存放位置，核心问题在于子序列，所以动态规划不合适
//单调栈不合适,因为pop出的数字可能还有用
public int lengthOfLIS(int[] nums) {
int[] stack = new int[nums.length];
int index = 0;
stack[index] = nums[0];
for (int i = 1; i < nums.length; i++) {
if (stack[index] < nums[i]) {
stack[++index] = nums[i];
} else {
//找出第一个比他小的位置,并替代
for (int j = 0; j <= index; j++) {
if (stack[j] >= nums[i]) {
stack[j] = nums[i];
break;
}
}
}
}
return index+1;
}
}

87
Leecode/src/main/java/com/markilue/leecode/hot100/second/T79_301_RemoveInvalidParentheses.java Normal file
View File

@ -0,0 +1,87 @@
package com.markilue.leecode.hot100.second;
import org.junit.Test;
import java.util.ArrayList;
import java.util.List;
/**
*@BelongsProject: Leecode
*@BelongsPackage: com.markilue.leecode.hot100.second
*@Author: markilue
*@CreateTime: 2023-05-31 11:50
*@Description: TODO 力扣301 删除无效的括号
*@Version: 1.0
*/
public class T79_301_RemoveInvalidParentheses {
@Test
public void test() {
String s = "(a)())()";
System.out.println(removeInvalidParentheses(s));
}
//朴素的想法:判断左右括号哪个多，确定删除谁;然后挨个删，最后通过判断合不合适来加入结果
public List<String> removeInvalidParentheses(String s) {
int left = 0;
int right = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == '(') {
left++;
} else if (s.charAt(i) == ')') {
if (left > 0) {
left--;
} else {
right++;
}
}
}
List<String> result = new ArrayList<>();
removeHelper(s, left, right, result,0);
return result;
}
//需要注意这个start；一定要从这个字母后面开始删除
public void removeHelper(String s, int left, int right, List<String> res,int start) {
if (left == 0 && right == 0) {
if (isValid(s)) {
res.add(new String(s));
}
return;
}
for (int i = start; i < s.length(); i++) {
if (i > 0 && s.charAt(i) == s.charAt(i - 1)) continue;//去重
if (left + right > s.length() - i) {
//怎么删都不够了
return;
}
if (left > 0 && s.charAt(i) == '(') {
removeHelper(s.substring(0, i) + s.substring(i + 1), left - 1, right, res,i);
}
if (right > 0 && s.charAt(i) == ')') {
removeHelper(s.substring(0, i) + s.substring(i + 1), left, right - 1, res,i);
}
}
}
private boolean isValid(String s) {
int left = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == '(') {
left++;
} else if (s.charAt(i) == ')') {
left--;
if (left < 0) return false;
}
}
return true;
}
}

39
Leecode/src/main/java/com/markilue/leecode/hot100/second/T80_309_MaxProfit.java Normal file
View File

@ -0,0 +1,39 @@
package com.markilue.leecode.hot100.second;
/**
*@BelongsProject: Leecode
*@BelongsPackage: com.markilue.leecode.hot100.second
*@Author: markilue
*@CreateTime: 2023-05-31 13:22
*@Description: TODO 力扣309 最佳买卖股票时机含冷冻期
*@Version: 1.0
*/
public class T80_309_MaxProfit {
/**
* 动态规划:
* 状态分为：
* 1.今天没有股票(不在冷冻期)
* 2.今天没有股票(在冷冻期) ->刚刚卖出
* 3.今天买了股票
* @param prices
* @return
*/
public int maxProfit(int[] prices) {
//对应状态1 2 3
int dp0 = 0;
int dp1 = 0;
int dp2 = -prices[0];
int temp;
for (int i = 0; i < prices.length; i++) {
temp = dp0;
dp0 = Math.max(dp0, dp1);//昨天就没买股票;昨天在冷冻期
dp1 = dp2 + prices[i];//昨天有股票,今天卖了
dp2 = Math.max(dp2, temp - prices[i]);//昨天有股票；昨天没股票且不再冷冻期，今天买了
}
return Math.max(dp0, dp1);
}
}