feat: 56. Merge Intervals : 扫描线

Author: upupming

leetcode/残酷刷题/56. Merge Intervals.js

@@ -0,0 +1,24 @@
+function merge(intervals: number[][]): number[][] {
+  const a = []
+  for (const [s, e] of intervals) {
+      a.push([s, 1], [e, -1])
+  }
+  a.sort((x, y) => {
+      if (x[0] === y[0]) {
+          return -(x[1] - y[1])
+      }
+      return x[0]-y[0]
+  })
+  let cnt = 0, ans = [], tmp = []
+  for (const t of a) {
+      cnt += t[1]
+      if (t[1] === 1 && cnt === 1) {
+          tmp.push(t[0])
+      } else if (cnt === 0) {
+          tmp.push(t[0])
+          ans.push(tmp)
+          tmp = []
+      }
+  }
+  return ans
+};

leetcode/残酷刷题/README.md

@@ -36,6 +36,7 @@
         - [字符串哈希](#字符串哈希)
         - [括号匹配](#括号匹配)
         - [分治 (Divide and Conquer)](#分治-divide-and-conquer)
+        - [扫描线 (Sweep Line)](#扫描线-sweep-line)
     - [Links](#links)
 
 ## Problems
@@ -266,6 +267,10 @@
 - 315. Count of Smaller Numbers After Self
 - 2179. Count Good Triplets in an Array
 
+### 扫描线 (Sweep Line)
+
+- 56. Merge Intervals
+
 ## Links
 
 - https://wisdompeak.github.io/lc-score-board/