feat: 1648. Sell Diminishing-Valued Colored Balls : 二分

Author: upupming

leetcode/残酷刷题/1648. Sell Diminishing-Valued Colored Balls.js

@@ -0,0 +1,35 @@
+/**
+ * @param {number[]} inventory
+ * @param {number} orders
+ * @return {number}
+ */
+const maxProfit = function (inventory, orders) {
+  // >= mid 以上的都被售出
+  let l = 1; let r = 1e9
+  while (l < r) {
+    const mid = l + r + 1 >> 1
+    if (valid(mid)) l = mid
+    else r = mid - 1
+  }
+  function valid (m) {
+    let o = 0
+    for (const p of inventory) {
+      if (p >= m) o += (p - m + 1)
+    }
+    return o >= orders
+  }
+  let sum = 0n; let rest = orders
+  // l+1 先全部都选了再说
+  for (const p of inventory) {
+    if (p >= l + 1) {
+      const c = p - (l + 1) + 1
+      sum += BigInt(p + l + 1) * BigInt(c) / 2n
+      sum %= BigInt(1e9 + 7)
+      rest -= c
+    }
+  }
+  // 不够的全部都选 l
+  sum += BigInt(rest) * BigInt(l)
+  sum %= BigInt(1e9 + 7)
+  return sum
+}

leetcode/残酷刷题/README.md

@@ -143,6 +143,7 @@
 - 1802. Maximum Value at a Given Index in a Bounded Array
 - 1201. Ugly Number III.js
 - 二分 + 容斥原理 + lcm
+- 1648. Sell Diminishing-Valued Colored Balls
 
 ### 并查集