diff --git a/problems/0019.删除链表的倒数第N个节点.md b/problems/0019.删除链表的倒数第N个节点.md index a84c0b29..b9859968 100644 --- a/problems/0019.删除链表的倒数第N个节点.md +++ b/problems/0019.删除链表的倒数第N个节点.md @@ -338,5 +338,28 @@ object Solution { } } ``` + +Rust: +```rust +impl Solution { + pub fn remove_nth_from_end(head: Option>, mut n: i32) -> Option> { + let mut dummy_head = Box::new(ListNode::new(0)); + dummy_head.next = head; + let mut fast = &dummy_head.clone(); + let mut slow = &mut dummy_head; + while n > 0 { + fast = fast.next.as_ref().unwrap(); + n -= 1; + } + while fast.next.is_some() { + fast = fast.next.as_ref().unwrap(); + slow = slow.next.as_mut().unwrap(); + } + slow.next = slow.next.as_mut().unwrap().next.take(); + dummy_head.next + } +} +``` + -----------------------
diff --git a/problems/0024.两两交换链表中的节点.md b/problems/0024.两两交换链表中的节点.md index 10337a7f..d65d0bca 100644 --- a/problems/0024.两两交换链表中的节点.md +++ b/problems/0024.两两交换链表中的节点.md @@ -380,5 +380,51 @@ function swapPairs($head) } ``` +Rust: + +```rust +// 虚拟头节点 +impl Solution { + pub fn swap_pairs(head: Option>) -> Option> { + let mut dummy_head = Box::new(ListNode::new(0)); + dummy_head.next = head; + let mut cur = dummy_head.as_mut(); + while let Some(mut node) = cur.next.take() { + if let Some(mut next) = node.next.take() { + node.next = next.next.take(); + next.next = Some(node); + cur.next = Some(next); + cur = cur.next.as_mut().unwrap().next.as_mut().unwrap(); + } else { + cur.next = Some(node); + cur = cur.next.as_mut().unwrap(); + } + } + dummy_head.next + } +} +``` + +```rust +// 递归 +impl Solution { + pub fn swap_pairs(head: Option>) -> Option> { + if head == None || head.as_ref().unwrap().next == None { + return head; + } + + let mut node = head.unwrap(); + + if let Some(mut next) = node.next.take() { + node.next = Solution::swap_pairs(next.next); + next.next = Some(node); + Some(next) + } else { + Some(node) + } + } +} +``` + -----------------------
diff --git a/problems/0035.搜索插入位置.md b/problems/0035.搜索插入位置.md index 4b17bec6..cd2c88eb 100644 --- a/problems/0035.搜索插入位置.md +++ b/problems/0035.搜索插入位置.md @@ -429,7 +429,57 @@ function searchInsert($nums, $target) return $r + 1; } ``` - +### C +```c +//版本一 [left, right]左闭右闭区间 +int searchInsert(int* nums, int numsSize, int target){ + //左闭右开区间 [0 , numsSize-1] + int left =0; + int mid =0; + int right = numsSize - 1; + while(left <= right){//左闭右闭区间 所以可以 left == right + mid = left + (right - left) / 2; + if(target < nums[mid]){ + //target 在左区间 [left, mid - 1]中，原区间包含mid，右区间边界可以向左内缩 + right = mid -1; + }else if( target > nums[mid]){ + //target 在右区间 [mid + 1, right]中,原区间包含mid，左区间边界可以向右内缩 + left = mid + 1; + }else { + // nums[mid] == target ，顺利找到target，直接返回mid + return mid; + } + } + //数组中未找到target元素 + //target在数组所有元素之后，[left, right]是右闭区间，需要返回 right +1 + return right + 1; +} +``` +```c +//版本二 [left, right]左闭右开区间 +int searchInsert(int* nums, int numsSize, int target){ + //左闭右开区间 [0 , numsSize) + int left =0; + int mid =0; + int right = numsSize; + while(left < right){//左闭右闭区间 所以 left < right + mid = left + (right - left) / 2; + if(target < nums[mid]){ + //target 在左区间 [left, mid)中，原区间没有包含mid，右区间边界不能内缩 + right = mid ; + }else if( target > nums[mid]){ + // target 在右区间 [mid+1, right)中，原区间包含mid，左区间边界可以向右内缩 + left = mid + 1; + }else { + // nums[mid] == target ，顺利找到target，直接返回mid + return mid; + } + } + //数组中未找到target元素 + //target在数组所有元素之后，[left, right)是右开区间， return right即可 + return right; +} +``` -----------------------
diff --git a/problems/0072.编辑距离.md b/problems/0072.编辑距离.md index df5d37c2..df57b5b8 100644 --- a/problems/0072.编辑距离.md +++ b/problems/0072.编辑距离.md @@ -364,6 +364,7 @@ function minDistance(word1: string, word2: string): number { C： + ```c int min(int num1, int num2, int num3) { return num1 > num2 ? (num2 > num3 ? num3 : num2) : (num1 > num3 ? num3 : num1); diff --git a/problems/0090.子集II.md b/problems/0090.子集II.md index 9e7e3bd0..81c0f94a 100644 --- a/problems/0090.子集II.md +++ b/problems/0090.子集II.md @@ -367,6 +367,39 @@ function subsetsWithDup(nums: number[]): number[][] { }; ``` +set去重版本: +```typescript +// 使用set去重版本 +function subsetsWithDup(nums: number[]): number[][] { + const result: number[][] = []; + const path: number[] = []; + // 去重之前先排序 + nums.sort((a, b) => a - b); + function backTracking(startIndex: number) { + // 收集结果 + result.push([...path]) + // 此处不返回也可以因为，每次递归都会使startIndex + 1，当这个数大到nums.length的时候就不会进入递归了。 + if (startIndex === nums.length) { + return + } + // 定义每一个树层的set集合 + const set: Set = new Set() + for (let i = startIndex; i < nums.length; i++) { + // 去重 + if (set.has(nums[i])) { + continue + } + set.add(nums[i]) + path.push(nums[i]) + backTracking(i + 1) + // 回溯 + path.pop() + } + } + backTracking(0) + return result +}; +``` ### Rust ```Rust diff --git a/problems/0150.逆波兰表达式求值.md b/problems/0150.逆波兰表达式求值.md index 13b2ba46..376948cf 100644 --- a/problems/0150.逆波兰表达式求值.md +++ b/problems/0150.逆波兰表达式求值.md @@ -89,26 +89,29 @@ C++代码如下： class Solution { public: int evalRPN(vector& tokens) { - stack st; + // 力扣修改了后台测试数据，需要用longlong + stack st; for (int i = 0; i < tokens.size(); i++) { if (tokens[i] == "+" || tokens[i] == "-" || tokens[i] == "*" || tokens[i] == "/") { - int num1 = st.top(); + long long num1 = st.top(); st.pop(); - int num2 = st.top(); + long long num2 = st.top(); st.pop(); if (tokens[i] == "+") st.push(num2 + num1); if (tokens[i] == "-") st.push(num2 - num1); if (tokens[i] == "*") st.push((long)num2 * (long)num1); //力扣改了后台测试数据 if (tokens[i] == "/") st.push(num2 / num1); } else { - st.push(stoi(tokens[i])); + st.push(stoll(tokens[i])); } } + int result = st.top(); st.pop(); // 把栈里最后一个元素弹出（其实不弹出也没事） return result; } }; + ``` ## 题外话 diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md index e97befee..009b4469 100644 --- a/problems/0206.翻转链表.md +++ b/problems/0206.翻转链表.md @@ -588,5 +588,45 @@ object Solution { } ``` + +Rust: +双指针法： + +```rust +impl Solution { + pub fn reverse_list(head: Option>) -> Option> { + let mut cur = head; + let mut pre = None; + while let Some(mut node) = cur.take() { + cur = node.next; + node.next = pre; + pre = Some(node); + } + pre + } +} +``` + +递归法： + +```rust +impl Solution { + pub fn reverse_list(head: Option>) -> Option> { + fn rev( + mut head: Option>, + mut pre: Option>, + ) -> Option> { + if let Some(mut node) = head.take() { + let cur = node.next; + node.next = pre; + pre = Some(node); + return rev(cur, pre); + } + pre + } + rev(head, None) + } +} +``` -----------------------
diff --git a/problems/0455.分发饼干.md b/problems/0455.分发饼干.md index f9e8e7f1..93a4c2d3 100644 --- a/problems/0455.分发饼干.md +++ b/problems/0455.分发饼干.md @@ -274,6 +274,7 @@ function findContentChildren(g: number[], s: number[]): number { ### C ```c +///小餅乾先餵飽小胃口的 int cmp(int* a, int* b) { return *a - *b; } @@ -296,6 +297,33 @@ int findContentChildren(int* g, int gSize, int* s, int sSize){ } ``` +```c +///大餅乾先餵飽大胃口的 +int cmp(int* a, int* b) { + return *a - *b; +} + +int findContentChildren(int* g, int gSize, int* s, int sSize){ + if(sSize == 0) + return 0; + + //将两个数组排序为升序 + qsort(g, gSize, sizeof(int), cmp); + qsort(s, sSize, sizeof(int), cmp); + + int count = 0; + int start = sSize - 1; + + for(int i = gSize - 1; i >= 0; i--) { + if(start >= 0 && s[start] >= g[i] ) { + start--; + count++; + } + } + return count; +} +``` + ### Scala ```scala diff --git a/problems/0583.两个字符串的删除操作.md b/problems/0583.两个字符串的删除操作.md index fd80853e..c33f7f58 100644 --- a/problems/0583.两个字符串的删除操作.md +++ b/problems/0583.两个字符串的删除操作.md @@ -47,6 +47,8 @@ dp[i][j]：以i-1为结尾的字符串word1，和以j-1位结尾的字符串word 那最后当然是取最小值，所以当word1[i - 1] 与 word2[j - 1]不相同的时候，递推公式：dp[i][j] = min({dp[i - 1][j - 1] + 2, dp[i - 1][j] + 1, dp[i][j - 1] + 1}); +因为dp[i - 1][j - 1] + 1等于 dp[i - 1][j] 或 dp[i][j - 1]，所以递推公式可简化为：dp[i][j] = min(dp[i - 1][j] + 1, dp[i][j - 1] + 1); + 3. dp数组如何初始化 @@ -90,7 +92,7 @@ public: if (word1[i - 1] == word2[j - 1]) { dp[i][j] = dp[i - 1][j - 1]; } else { - dp[i][j] = min({dp[i - 1][j - 1] + 2, dp[i - 1][j] + 1, dp[i][j - 1] + 1}); + dp[i][j] = min(dp[i - 1][j] + 1, dp[i][j - 1] + 1); } } } diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md index 83e57fec..1f7e6cbf 100644 --- a/problems/0707.设计链表.md +++ b/problems/0707.设计链表.md @@ -1240,6 +1240,94 @@ class MyLinkedList() { } ``` +Rust: + +```rust +#[derive(Debug)] +pub struct MyLinkedList { + pub val: i32, + pub next: Option>, +} + +impl MyLinkedList { + fn new() -> Self { + // 增加头节点 + MyLinkedList { val: 0, next: None } + } + + fn get(&self, index: i32) -> i32 { + if index < 0 { + return -1; + } + let mut i = 0; + let mut cur = &self.next; + while let Some(node) = cur { + if i == index { + return node.val; + } + i += 1; + cur = &node.next; + } + -1 + } + + fn add_at_head(&mut self, val: i32) { + let new_node = Box::new(MyLinkedList { + val, + next: self.next.take(), + }); + self.next = Some(new_node); + } + + fn add_at_tail(&mut self, val: i32) { + let new_node = Box::new(MyLinkedList { val, next: None }); + let mut last_node = &mut self.next; + while let Some(node) = last_node { + last_node = &mut node.next; + } + *last_node = Some(new_node); + } + + fn add_at_index(&mut self, index: i32, val: i32) { + if index <= 0 { + self.add_at_head(val); + } else { + let mut i = 0; + let mut cur = &mut self.next; + while let Some(node) = cur { + if i + 1 == index { + let new_node = Box::new(MyLinkedList { + val, + next: node.next.take(), + }); + node.next = Some(new_node); + break; + } + i += 1; + cur = &mut node.next; + } + } + } + + fn delete_at_index(&mut self, index: i32) { + if index < 0 { + return; + } + + let mut i = 0; + let mut cur = self; + while let Some(node) = cur.next.take() { + if i == index { + cur.next = node.next; + break; + } + i += 1; + cur.next = Some(node); + cur = cur.next.as_mut().unwrap(); + } + } +} +``` -----------------------