Create 1840-maximum-building-height.js

Author: everthis

1840-maximum-building-height.js

@@ -0,0 +1,46 @@
+/**
+ * @param {number} n
+ * @param {number[][]} restrictions
+ * @return {number}
+ */
+var maxBuilding = function (n, restrictions) {
+  restrictions.sort((a, b) => a[0] - b[0]);
+  let prevInd = 1,
+    prevH = 0;
+  for (let i = 0; i < restrictions.length; i++) {
+    restrictions[i][1] = Math.min(
+      restrictions[i][1],
+      prevH + (restrictions[i][0] - prevInd)
+    );
+    prevInd = restrictions[i][0];
+    prevH = restrictions[i][1];
+  }
+
+  for (let i = restrictions.length - 2; i >= 0; i--) {
+    restrictions[i][1] = Math.min(
+      restrictions[i][1],
+      restrictions[i + 1][1] + (restrictions[i + 1][0] - restrictions[i][0])
+    );
+  }
+
+  let ph = 0,
+    pInd = 1,
+    highest = 0;
+  for (let i = 0; i < restrictions.length; i++) {
+    let ind = restrictions[i][0];
+    let h = restrictions[i][1];
+    if (ph < h) {
+      h = Math.min(h, ph + (ind - pInd));
+
+      let remains = Math.max(0, ind - pInd - (h - ph));
+      highest = Math.max(highest, h + ~~(remains / 2));
+    } else {
+      let remains = ind - pInd - (ph - h);
+      highest = Math.max(highest, ph + ~~(remains / 2));
+    }
+    ph = h;
+    pInd = ind;
+  }
+  highest = Math.max(highest, ph + (n - pInd));
+  return highest;
+};