合并区间.js

// s1 s2 s1[1] >= s2[0]
// current next
/**
 * @param {number[][]} intervals
 * @return {number[][]}
 56. 合并区间
 */
 var merge = function(intervals) {
  let ans = []
  let len = intervals.length
  let index = 0
  let current = []
  intervals.sort((prev, next) => prev[0] - next[0])
  while(index < len) {
      next = intervals[index++]
      if (current.length === 0) {
          current = next
      } else {
          if(current[1] >= next[0]) {
              current = [current[0], Math.max(current[1], next[1])]
          }else{
              ans.push([...current])
              current = next
          }
      }
  }
  if(current.length > 0) {
      ans.push([...current])
  }
  return ans
};