Merge remote-tracking branch 'origin/master'

Dream · Dream · commit 6095bd69ff13 · 2022-01-17T10:04:09.000+08:00
diff --git a/README.md b/README.md
@@ -414,7 +414,7 @@
 |31|[Next Permutation](https://leetcode.com/problems/next-permutation/)| |Medium|
 |30|[Substring with Concatenation of All Words](https://leetcode.com/problems/substring-with-concatenation-of-all-words/)| |Hard|
 |29|[Divide Two Integers](https://leetcode.com/problems/divide-two-integers/)| |Medium|
-|28|[Implement strStr()](https://leetcode.com/problems/implement-strstr/)| |Easy|
+|28|[Implement strStr()](https://leetcode.com/problems/implement-strstr/)| [js](./algorithms/implementStrstr/solution.js) |Easy|
 |27|[Remove Element](https://leetcode.com/problems/remove-element/)| [js](./algorithms/removeElement/removeElement.js) [python](./algorithms/removeElement/removeElement.python) |Easy|
 |26|[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/)| [java](./algorithms/removeDuplicatesFromSortedArray/Solution.java), [js](./algorithms/removeDuplicatesFromSortedArray/Solution.js)  |Easy|
 |25|[Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/)| |Hard|
diff --git a/algorithms/implementStrstr/solution.js b/algorithms/implementStrstr/solution.js
@@ -0,0 +1,28 @@
+// 解法一：用 js 现成的 indexOf api
+var strStr = function(haystack, needle) {
+    if(!needle) return 0;
+    return haystack.indexOf(needle)
+};
+
+
+// TODO: 解法二：自己实现
+// var strStr = function(haystack, needle) {
+//     // 不存在或者相等时，返回0
+//     if (!needle || needle === haystack) return 0;
+//     let h = 0, n = 0, index = 0;
+//     while (h < haystack.length && haystack.length < needle.length) {
+//         while (haystack[h] === needle[n] && n < needle.length) {
+//             if (index === 0) {
+//                 index = h
+//             }
+//             n = n + 1;
+//         }
+//         if (n === needle.length) {
+//             return index;
+//         } else {
+//             h = h + 1;
+//         }
+//     }
+//     // 找不到或者要查找的字符串大于自己的时候，返回-1
+//     return -1;
+// };
diff --git a/algorithms/isPalindrome/isPalindrome.js b/algorithms/isPalindrome/isPalindrome.js
@@ -0,0 +1,13 @@
+var isPalindrome = function(x) {
+    // 负数 0 10和10的倍数不可能为回文数
+    if (x <= 0 || (!(x % 10) && x)) return false;
+    let x2 = x, res = 0;
+    while (x2) {
+      res = res * 10 + x2 % 10;
+      // x2 = ~~(x2 / 10);
+      // ~~ 运算符处理大于32位数值时，为负数，可以换成Math.floor()
+      x2 = Math.floor(x2 / 10);
+    }
+
+    return res === x;
+};
diff --git a/algorithms/longestCommonPrefix-jcc/index.html b/algorithms/longestCommonPrefix-jcc/index.html
@@ -9,5 +9,5 @@
 <body>
   
 </body>
-<script src="./addTwoNumbers.js"></script>
+<script src="./longestCommonPrefix.js"></script>
 </html>
diff --git a/algorithms/longestCommonPrefix-jcc/longestCommonPrefix.js b/algorithms/longestCommonPrefix-jcc/longestCommonPrefix.js
@@ -0,0 +1,15 @@
+var longestCommonPrefix = function(strs) {
+  if(strs.length == 0) return "";
+  let str = strs[0]; // 取第一个用来做基准比较
+  for(let i = 1; i<strs.length; i++) { // 不需要跟自己比较，从1开始
+      let j = 0;
+      for(;j<str.length && j<strs[i].length; j++) {
+        if(str[j] != strs[i][j]) break; // 有不想等的就跳出循环
+      }
+      str = str.substr(0, j); // 截取相等的部分
+      if(str === "") return str;
+  }
+  return str;
+};
+
+console.log(longestCommonPrefix(["flower","flow","flight"]));
diff --git a/algorithms/twoCityScheduling/TwoCityScheduling.java b/algorithms/twoCityScheduling/TwoCityScheduling.java
@@ -0,0 +1,21 @@
+class TwoCityScheduling {
+    public int twoCitySchedCost(int[][] costs) {
+        int sum = 0;
+        int[] ar = new int[2000];
+        for (int[] iArray : costs) {
+            sum = sum + iArray[0];
+            ar[iArray[1] - iArray[0] +1000]++;
+        }
+        int index = 0;
+        int i = 0;
+        while (i < costs.length / 2) {
+            while (ar[index] > 0 && i<costs.length/2) {
+                sum = sum + (index -1000);
+                ar[index]--;
+                i++;
+            }
+            index++;
+        }
+        return sum;
+    }
+}
