feat: leetcode contest 300

Author: upupming

leetcode/contest-300/6108. Decode the Message.js

@@ -0,0 +1,16 @@
+/**
+ * @param {string} key
+ * @param {string} message
+ * @return {string}
+ */
+const decodeMessage = function (key, message) {
+  const mp = {}; let c = 0
+  for (const ch of key) {
+    if (ch === ' ') continue
+    if (mp[ch] == null) mp[ch] = String.fromCharCode((c++) + 'a'.charCodeAt(0))
+  }
+  return message.split('').map(x => {
+    if (x === ' ') return x
+    return mp[x]
+  }).join('')
+}

leetcode/contest-300/6109. Number of People Aware of a Secret.js

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+/**
+ * @param {number} n
+ * @param {number} delay
+ * @param {number} forget
+ * @return {number}
+ */
+const peopleAwareOfSecret = function (n, d, f) {
+  const a = [[1, 0]]; let ans = 1; const P = 1e9 + 7
+  for (let i = 1; i < n; i++) {
+    while (a.length && i - a[0][1] >= f) ans = (ans - a[0][0] + P) % P, a.shift()
+    let j = a.length - 1
+    while (j >= 0 && a[j][1] > i - d) j--
+    let tmp = 0
+    for (let k = j; k >= 0; k--) tmp = (tmp + a[k][0]) % P
+    // console.log(i, a, ans)
+    a.push([tmp, i]), ans = (ans + tmp) % P
+  }
+  return ans
+}

leetcode/contest-300/6110. Number of Increasing Paths in a Grid.js

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+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+const countPaths = function (g) {
+  const dx = [0, 0, 1, -1]; const dy = [1, -1, 0, 0]
+  const m = g.length; const n = g[0].length
+  const mp = {}; const P = 1e9 + 7
+  const dfs = (i, j) => {
+    if (mp[`${i}_${j}`] != null) return mp[`${i}_${j}`]
+    let ans = 1
+    for (let k = 0; k < 4; k++) {
+      const x = i + dx[k]; const y = j + dy[k]
+      if (x >= 0 && x < m && y >= 0 && y < n && g[i][j] < g[x][y]) ans = (ans + dfs(x, y)) % P
+    }
+    return mp[`${i}_${j}`] = ans
+  }
+  let ans = 0
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      ans = (ans + dfs(i, j)) % P
+    }
+  }
+  return ans
+}

leetcode/contest-300/6111. Spiral Matrix IV.js

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+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {number} m
+ * @param {number} n
+ * @param {ListNode} head
+ * @return {number[][]}
+ */
+const spiralMatrix = function (m, n, h) {
+  const ans = Array(m).fill(0).map(() => Array(n).fill(-1))
+  let i = 0; let j = 0
+  const dx = [0, 1, 0, -1]; const dy = [1, 0, -1, 0]; let cd = 0
+  while (h) {
+    ans[i][j] = h.val
+    let ni = i + dx[cd]; let nj = j + dy[cd]
+    if (ni < 0 || ni >= m || nj < 0 || nj >= n || ans[ni][nj] !== -1) cd = (cd + 1) % 4
+    ni = i + dx[cd], nj = j + dy[cd]
+    i = ni, j = nj
+    h = h.next
+  }
+  return ans
+}