diff --git a/problems/0028.实现strStr.md b/problems/0028.实现strStr.md index 634d8535..d67e5f70 100644 --- a/problems/0028.实现strStr.md +++ b/problems/0028.实现strStr.md @@ -1059,5 +1059,112 @@ func getNext(_ next: inout [Int], needle: [Character]) { ``` +> 前缀表右移 + +```swift +func strStr(_ haystack: String, _ needle: String) -> Int { + + let s = Array(haystack), p = Array(needle) + guard p.count != 0 else { return 0 } + + var j = 0 + var next = [Int].init(repeating: 0, count: p.count) + getNext(&next, p) + + for i in 0 ..< s.count { + + while j > 0 && s[i] != p[j] { + j = next[j] + } + + if s[i] == p[j] { + j += 1 + } + + if j == p.count { + return i - p.count + 1 + } + } + + return -1 + } + + // 前缀表后移一位，首位用 -1 填充 + func getNext(_ next: inout [Int], _ needle: [Character]) { + + guard needle.count > 1 else { return } + + var j = 0 + next[0] = j + + for i in 1 ..< needle.count-1 { + + while j > 0 && needle[i] != needle[j] { + j = next[j-1] + } + + if needle[i] == needle[j] { + j += 1 + } + + next[i] = j + } + next.removeLast() + next.insert(-1, at: 0) + } +``` + +> 前缀表统一不减一 +```swift + +func strStr(_ haystack: String, _ needle: String) -> Int { + + let s = Array(haystack), p = Array(needle) + guard p.count != 0 else { return 0 } + + var j = 0 + var next = [Int](repeating: 0, count: needle.count) + // KMP + getNext(&next, needle: p) + + for i in 0 ..< s.count { + while j > 0 && s[i] != p[j] { + j = next[j-1] + } + + if s[i] == p[j] { + j += 1 + } + + if j == p.count { + return i - p.count + 1 + } + } + return -1 + } + + //前缀表 + func getNext(_ next: inout [Int], needle: [Character]) { + + var j = 0 + next[0] = j + + for i in 1 ..< needle.count { + + while j>0 && needle[i] != needle[j] { + j = next[j-1] + } + + if needle[i] == needle[j] { + j += 1 + } + + next[i] = j + + } + } + +``` + -----------------------
diff --git a/problems/0093.复原IP地址.md b/problems/0093.复原IP地址.md index 7910fc50..6401824b 100644 --- a/problems/0093.复原IP地址.md +++ b/problems/0093.复原IP地址.md @@ -227,7 +227,7 @@ private: public: vector restoreIpAddresses(string s) { result.clear(); - if (s.size() > 12) return result; // 算是剪枝了 + if (s.size() < 4 || s.size() > 12) return result; // 算是剪枝了 backtracking(s, 0, 0); return result; } diff --git a/problems/0106.从中序与后序遍历序列构造二叉树.md b/problems/0106.从中序与后序遍历序列构造二叉树.md index 7ecca773..188ad3cb 100644 --- a/problems/0106.从中序与后序遍历序列构造二叉树.md +++ b/problems/0106.从中序与后序遍历序列构造二叉树.md @@ -103,7 +103,7 @@ TreeNode* traversal (vector& inorder, vector& postorder) { 中序数组相对比较好切，找到切割点（后序数组的最后一个元素）在中序数组的位置，然后切割，如下代码中我坚持左闭右开的原则： -```C++ +```CPP // 找到中序遍历的切割点 int delimiterIndex; for (delimiterIndex = 0; delimiterIndex < inorder.size(); delimiterIndex++) { @@ -130,7 +130,7 @@ vector rightInorder(inorder.begin() + delimiterIndex + 1, inorder.end() ); 代码如下： -``` +```CPP // postorder 舍弃末尾元素，因为这个元素就是中间节点，已经用过了 postorder.resize(postorder.size() - 1); @@ -144,7 +144,7 @@ vector rightPostorder(postorder.begin() + leftInorder.size(), postorder.end 接下来可以递归了，代码如下： -``` +```CPP root->left = traversal(leftInorder, leftPostorder); root->right = traversal(rightInorder, rightPostorder); ``` diff --git a/problems/0209.长度最小的子数组.md b/problems/0209.长度最小的子数组.md index 82a11381..fd72cf1b 100644 --- a/problems/0209.长度最小的子数组.md +++ b/problems/0209.长度最小的子数组.md @@ -198,7 +198,7 @@ JavaScript: var minSubArrayLen = function(target, nums) { // 长度计算一次 const len = nums.length; - let l = r = sum = 0, + let l = r = sum = 0, res = len + 1; // 子数组最大不会超过自身 while(r < len) { sum += nums[r++]; @@ -260,12 +260,12 @@ Rust: ```rust impl Solution { - pub fn min_sub_array_len(target: i32, nums: Vec) -> i32 { + pub fn min_sub_array_len(target: i32, nums: Vec) -> i32 { let (mut result, mut subLength): (i32, i32) = (i32::MAX, 0); let (mut sum, mut i) = (0, 0); - + for (pos, val) in nums.iter().enumerate() { - sum += val; + sum += val; while sum >= target { subLength = (pos - i + 1) as i32; if result > subLength { @@ -364,7 +364,7 @@ int minSubArrayLen(int target, int* nums, int numsSize){ int minLength = INT_MAX; int sum = 0; - int left = 0, right = 0; + int left = 0, right = 0; //右边界向右扩展 for(; right < numsSize; ++right) { sum += nums[right]; @@ -380,5 +380,26 @@ int minSubArrayLen(int target, int* nums, int numsSize){ } ``` +Kotlin: +```kotlin +class Solution { + fun minSubArrayLen(target: Int, nums: IntArray): Int { + var start = 0 + var end = 0 + var ret = Int.MAX_VALUE + var count = 0 + while (end < nums.size) { + count += nums[end] + while (count >= target) { + ret = if (ret > (end - start + 1)) end - start + 1 else ret + count -= nums[start++] + } + end++ + } + return if (ret == Int.MAX_VALUE) 0 else ret + } +} +``` + -----------------------
diff --git a/problems/0332.重新安排行程.md b/problems/0332.重新安排行程.md index f7ef8cf7..c71b2a93 100644 --- a/problems/0332.重新安排行程.md +++ b/problems/0332.重新安排行程.md @@ -342,7 +342,7 @@ class Solution: return path ``` -### Go +### GO ```go type pair struct { target string diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md index 00707347..5d9e8295 100644 --- a/problems/0383.赎金信.md +++ b/problems/0383.赎金信.md @@ -84,6 +84,10 @@ class Solution { public: bool canConstruct(string ransomNote, string magazine) { int record[26] = {0}; + //add + if (ransomNote.size() > magazine.size()) { + return false; + } for (int i = 0; i < magazine.length(); i++) { // 通过recode数据记录 magazine里各个字符出现次数 record[magazine[i]-'a'] ++; diff --git a/problems/0452.用最少数量的箭引爆气球.md b/problems/0452.用最少数量的箭引爆气球.md index 33bbad55..2ab14b61 100644 --- a/problems/0452.用最少数量的箭引爆气球.md +++ b/problems/0452.用最少数量的箭引爆气球.md @@ -193,7 +193,7 @@ func min(a,b int) int{ } return a } -``` +``` ### Javascript ```Javascript @@ -214,7 +214,31 @@ var findMinArrowShots = function(points) { }; ``` +### TypeScript + +```typescript +function findMinArrowShots(points: number[][]): number { + const length: number = points.length; + if (length === 0) return 0; + points.sort((a, b) => a[0] - b[0]); + let resCount: number = 1; + let right: number = points[0][1]; // 右边界 + let tempPoint: number[]; + for (let i = 1; i < length; i++) { + tempPoint = points[i]; + if (tempPoint[0] > right) { + resCount++; + right = tempPoint[1]; + } else { + right = Math.min(right, tempPoint[1]); + } + } + return resCount; +}; +``` + ### C + ```c int cmp(const void *a,const void *b) { diff --git a/problems/0459.重复的子字符串.md b/problems/0459.重复的子字符串.md index ccfb485c..a51c68ee 100644 --- a/problems/0459.重复的子字符串.md +++ b/problems/0459.重复的子字符串.md @@ -421,5 +421,89 @@ function repeatedSubstringPattern(s: string): boolean { }; ``` + +Swift: + +> 前缀表统一减一 +```swift + func repeatedSubstringPattern(_ s: String) -> Bool { + + let sArr = Array(s) + let len = s.count + if len == 0 { + return false + } + var next = Array.init(repeating: -1, count: len) + + getNext(&next,sArr) + + if next.last != -1 && len % (len - (next[len-1] + 1)) == 0{ + return true + } + + return false + } + + func getNext(_ next: inout [Int], _ str:[Character]) { + + var j = -1 + next[0] = j + + for i in 1 ..< str.count { + + while j >= 0 && str[j+1] != str[i] { + j = next[j] + } + + if str[i] == str[j+1] { + j += 1 + } + + next[i] = j + } + } +``` + +> 前缀表统一不减一 +```swift + func repeatedSubstringPattern(_ s: String) -> Bool { + + let sArr = Array(s) + let len = sArr.count + if len == 0 { + return false + } + + var next = Array.init(repeating: 0, count: len) + getNext(&next, sArr) + + if next[len-1] != 0 && len % (len - next[len-1]) == 0 { + return true + } + + return false + } + + // 前缀表不减一 + func getNext(_ next: inout [Int], _ sArr:[Character]) { + + var j = 0 + next[0] = 0 + + for i in 1 ..< sArr.count { + + while j > 0 && sArr[i] != sArr[j] { + j = next[j-1] + } + + if sArr[i] == sArr[j] { + j += 1 + } + + next[i] = j + } + } +``` + -----------------------
diff --git a/problems/二叉树的递归遍历.md b/problems/二叉树的递归遍历.md index 35d19d7b..612f2394 100644 --- a/problems/二叉树的递归遍历.md +++ b/problems/二叉树的递归遍历.md @@ -371,18 +371,18 @@ C: ```c //前序遍历： -void preOrderTraversal(struct TreeNode* root, int* ret, int* returnSize) { +void preOrder(struct TreeNode* root, int* ret, int* returnSize) { if(root == NULL) return; ret[(*returnSize)++] = root->val; - preOrderTraverse(root->left, ret, returnSize); - preOrderTraverse(root->right, ret, returnSize); + preOrder(root->left, ret, returnSize); + preOrder(root->right, ret, returnSize); } int* preorderTraversal(struct TreeNode* root, int* returnSize){ int* ret = (int*)malloc(sizeof(int) * 100); *returnSize = 0; - preOrderTraversal(root, ret, returnSize); + preOrder(root, ret, returnSize); return ret; } diff --git a/problems/背包问题理论基础完全背包.md b/problems/背包问题理论基础完全背包.md index faa1dc46..3ec399f1 100644 --- a/problems/背包问题理论基础完全背包.md +++ b/problems/背包问题理论基础完全背包.md @@ -37,7 +37,7 @@ * [动态规划：关于01背包问题，你该了解这些！（滚动数组）](https://programmercarl.com/背包理论基础01背包-2.html) 首先在回顾一下01背包的核心代码 -``` +```cpp for(int i = 0; i < weight.size(); i++) { // 遍历物品 for(int j = bagWeight; j >= weight[i]; j--) { // 遍历背包容量 dp[j] = max(dp[j], dp[j - weight[i]] + value[i]);