update

Author: tangweikun

CATEGORY.md

@@ -6,21 +6,8 @@ https://github.com/garciparedes
 
 https://garciparedes.me/#headers
 
-- Array +12
-
-  - [ ] 15
-  - [ ] 18
-  - [ ] 39
-  - [ ] 40
-  - [ ] 45
-  - [ ] 55
-  - [ ] 78
-  - [ ] 88
-  - [ ] 90
-
 - Backtracking
 
-  - [ ] 17
   - [ ] 22
   - [ ] 39
   - [ ] 40
@@ -36,6 +23,7 @@ https://garciparedes.me/#headers
   - [ ] 306
   - [ ] 357
   - [ ] 872
+    - [ ] 17
 
 - Breadth First Search +5
 
@@ -57,7 +45,6 @@ https://garciparedes.me/#headers
 
 - Dynamic Programming +7
 
-  - [ ] 376
   - [ ] 1143
   - [ ] 5
   - [ ] 91
@@ -69,6 +56,7 @@ https://garciparedes.me/#headers
       - [ ] 322
         - [ ] 343
         - [ ] 357
+        - [ ] 376
 
 - Greedy
 
@@ -129,3 +117,13 @@ https://garciparedes.me/#headers
 
   - [ ] 3
   - [ ] 16
+
+- Array +12
+
+  - [ ] 18
+    - [ ] 39
+      - [ ] 40
+      - [ ] 45
+        - [ ] 55
+          - [ ] 78
+            - [ ] 90

src/1004-max-consecutive-ones-iii/20210722.js

@@ -0,0 +1,25 @@
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number}
+ */
+
+var longestOnes = function (nums, k) {
+  let [left, right, res, zeroCount] = [0, 0, 0, 0];
+
+  while (right < nums.length) {
+    if (nums[right] === 0) zeroCount++;
+    if (zeroCount <= k) {
+      res = Math.max(res, right - left + 1);
+    }
+
+    while (zeroCount > k) {
+      if (nums[left] === 0) zeroCount--;
+      left++;
+    }
+
+    right++;
+  }
+
+  return res;
+};

src/1004-max-consecutive-ones-iii/index.js

@@ -1,27 +1,27 @@
-// HELP:
-
-/**
- * 滑动窗口
- * 时间：O(N), 88ms
- */
-var longestOnes = function(A, K) {
-  let zeroCount = 0;
-  let [left, right] = [0, 0];
-  let res = 0;
-
-  while (right < A.length) {
-    const newNumber = A[right++];
-    if (newNumber === 0) ++zeroCount;
-    if (zeroCount <= K) {
-      // 能替换所有0
-      res = Math.max(res, right - left);
-    }
-    while (zeroCount > K) {
-      // 不能替换的情况：删除字符
-      const oldNumber = A[left++];
-      if (oldNumber === 0) --zeroCount;
-    }
-  }
-
-  return res;
-};
+// HELP:
+
+/**
+ * 滑动窗口
+ * 时间：O(N), 88ms
+ */
+var longestOnes = function (nums, k) {
+  let [left, right, zeroCount, res] = [0, 0, 0, 0];
+
+  while (right < nums.length) {
+    if (nums[right] === 0) zeroCount++;
+
+    if (zeroCount <= k) {
+      // 能替换所有0
+      res = Math.max(res, right - left + 1);
+    }
+    while (zeroCount > k) {
+      // 不能替换的情况：删除字符
+      if (nums[left] === 0) zeroCount--;
+      left++;
+    }
+
+    right++;
+  }
+
+  return res;
+};

src/15-3Sum/20210729.js

@@ -0,0 +1,35 @@
+function threeSum(nums) {
+  if (nums.length < 3) return [];
+  nums.sort((x, y) => x - y);
+  const res = [];
+
+  for (let i = 0; i < nums.length - 2; i++) {
+    if (nums[i] === nums[i - 1]) continue;
+    let left = i + 1;
+    let right = nums.length - 1;
+    while (left < right) {
+      if (nums[i] + nums[left] + nums[right] === 0) {
+        res.push([nums[i], nums[left], nums[right]]);
+        left++;
+        right--;
+        while (nums[left] === nums[left - 1] && left < right) {
+          left++;
+        }
+        while (nums[right] === nums[right + 1] && left < right) {
+          right--;
+        }
+        continue;
+      }
+
+      if (nums[i] + nums[left] + nums[right] < 0) {
+        left++;
+      } else {
+        right--;
+      }
+    }
+  }
+
+  return res;
+}
+
+threeSum([-1, 0, 1, 2, -1, -4]);

src/17-letter-combinations-of-a-phone-number/index.js

@@ -1,38 +1,23 @@
-/**
- * @param {string} digits
- * @return {string[]}
- */
-var letterCombinations = function(digits) {
-  const hash = [
-    '',
-    '',
-    'abc',
-    'def',
-    'ghi',
-    'jkl',
-    'mno',
-    'pqrs',
-    'tuv',
-    'wxyz',
-  ];
-
-  const arr = digits.split('').map(n => hash[n]);
-  let res = [];
-  arr.length > 0 && backtrack(arr, []);
-
-  return res;
-
-  function backtrack(rest, temp) {
-    if (rest.length === 0) {
-      res.push(temp);
-      return;
-    }
-
-    const current = rest[0];
-    for (let char of current) {
-      backtrack(rest.slice(1), temp + char);
-    }
-  }
-};
-
-console.log(letterCombinations(''));
+/**
+ * @param {string} digits
+ * @return {string[]}
+ */
+var letterCombinations = function (digits) {
+  if (digits === "") return [];
+  const hash = ["", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"].map((x) => x.split(""));
+  const res = [];
+  dfs("", 0);
+  return res;
+
+  function dfs(temp, index) {
+    if (index === digits.length) {
+      return res.push(temp);
+    }
+
+    for (let char of hash[digits[index]]) {
+      dfs(temp + char, index + 1);
+    }
+  }
+};
+
+console.log(letterCombinations(""));

src/18-4Sum/20210729.js

@@ -0,0 +1,36 @@
+function fourSum(nums, target) {
+  if (nums.length < 4) return [];
+
+  nums.sort((x, y) => x - y);
+  const res = [];
+
+  for (let i = 0; i < nums.length - 3; i++) {
+    if (nums[i] === nums[i - 1]) continue;
+    for (let j = i + 1; j < nums.length - 2; j++) {
+      if (nums[j] === nums[j - 1] && j > i + 1) continue;
+      let l = j + 1;
+      let r = nums.length - 1;
+      while (l < r) {
+        if (nums[i] + nums[j] + nums[l] + nums[r] === target) {
+          res.push([nums[i], nums[j], nums[l], nums[r]]);
+          l++;
+          r--;
+          while (nums[l] === nums[l - 1] && l < r) {
+            l++;
+          }
+          while (nums[r] === nums[r + 1] && l < r) {
+            r--;
+          }
+        } else if (nums[i] + nums[j] + nums[l] + nums[r] < target) {
+          l++;
+        } else {
+          r--;
+        }
+      }
+    }
+  }
+
+  return res;
+}
+
+console.log(fourSum([-2, -1, -1, 1, 1, 2, 2], 0));

src/22-generate-parentheses/index.js

@@ -1,37 +1,24 @@
-/**
- * @param {number} n
- * @return {string[]}
- */
-var generateParenthesis = function(n) {
-  let res = ['()'];
-
-  let i = 2;
-
-  while (i <= n) {
-    let temp = [];
-    for (let j = 0; j < res.length; j++) {
-      const curr = res[j];
-      let k = 0;
-      while (k <= curr.length) {
-        const withLeft = [...curr];
-        withLeft.splice(k, 0, '(');
-
-        let m = k + 1;
-        while (m <= curr.length + 2) {
-          const withRight = [...withLeft];
-          withRight.splice(m, 0, ')');
-          m += 2;
-          temp.push(withRight.join(''));
-        }
-
-        k += 2;
-      }
-    }
-    res = Array.from(new Set(temp));
-    i++;
-  }
-
-  return res;
-};
-
-console.log(generateParenthesis(3));
+/**
+ * @param {number} n
+ * @return {string[]}
+ */
+var generateParenthesis = function (n) {
+  let res = [];
+  let temp = "";
+  dfs(temp, 0, 0);
+  return res;
+
+  function dfs(temp, left, right) {
+    if (left < right || left > n || right > n) {
+      return;
+    }
+    if (left === n && right === n) {
+      res.push(temp);
+      return;
+    }
+    dfs(temp + "(", left + 1, right);
+    dfs(temp + ")", left, right + 1);
+  }
+};
+
+console.log(generateParenthesis(3));

src/22-generate-parentheses/pro.js

@@ -1,30 +1,30 @@
-// HELP:
-/**
- * @param {number} n
- * @return {string[]}
- */
-var generateParenthesis = function(n) {
-  let res = [];
-
-  let temp = '';
-  let left = 0;
-  let right = 0;
-
-  backtrack(res, temp, left, right, n);
-  return res;
-
-  function backtrack(res, temp, left, right, n) {
-    // 减枝
-    if (left < right || left > n || right > n) {
-      return;
-    }
-    // 命中
-    if (left == n && right == n) {
-      res.push(temp);
-      return;
-    }
-    // 递归
-    backtrack(res, temp + '(', left + 1, right, n);
-    backtrack(res, temp + ')', left, right + 1, n);
-  }
-};
+// HELP:
+/**
+ * @param {number} n
+ * @return {string[]}
+ */
+var generateParenthesis = function (n) {
+  let res = [];
+
+  let temp = "";
+  let left = 0;
+  let right = 0;
+
+  backtrack(temp, left, right, n);
+  return res;
+
+  function backtrack(temp, left, right, n) {
+    // 减枝
+    if (left < right || left > n || right > n) {
+      return;
+    }
+    // 命中
+    if (left == n && right == n) {
+      res.push(temp);
+      return;
+    }
+    // 递归
+    backtrack(temp + "(", left + 1, right, n);
+    backtrack(temp + ")", left, right + 1, n);
+  }
+};