Update 2055-plates-between-candles.js

Author: everthis

2055-plates-between-candles.js

@@ -1,3 +1,52 @@
+/**
+ * @param {string} s
+ * @param {number[][]} queries
+ * @return {number[]}
+ */
+const platesBetweenCandles = function (s, queries) {
+  const candleIdxArr = []
+  const n = s.length
+  for(let i = 0; i < n; i++) {
+    if(s[i] === '|') candleIdxArr.push(i)
+  }
+  // console.log(candleIdxArr)
+  const res = []
+  for(const [s, e] of queries) {
+    const l = lower(candleIdxArr, s, e)
+    const r = upper(candleIdxArr, s ,e)
+    const tmp = (candleIdxArr[r] - candleIdxArr[l] + 1) - (r - l + 1)
+    res.push(tmp >= 0 ? tmp : 0)
+  }
+
+  return res
+
+
+  function lower(arr,s,e) {
+    let l = 0, r = arr.length - 1
+    while(l < r) {
+      // console.log('lower',l, r)
+      const mid = ~~(l + (r - l)/2)
+      if(arr[mid] < s) l = mid + 1
+      else r = mid
+    }
+    return l
+  }
+
+  function upper(arr,s, e) {
+    let l = 0, r = arr.length - 1
+    while(l < r) {
+
+      const mid = r - ~~((r - l)/2)
+      // console.log('upper', l, r, mid, e)
+      if(arr[mid] > e) r = mid - 1
+      else l = mid
+    }
+    return l
+  }
+}
+
+// another
+
 /**
  * @param {string} s
  * @param {number[][]} queries