832 833 835

Author: lazzzis

832/main.js

@@ -0,0 +1,23 @@
+/**
+ * @param {number[][]} A
+ * @return {number[][]}
+ */
+var flipAndInvertImage = function (A) {
+  for (const row of A) {
+    let i = 0
+    let j = row.length - 1
+    while (i <= j) {
+      [row[i], row[j]] = [row[j], row[i]]
+      i++
+      j--
+    }
+    for (let i = 0; i < row.length; i++) {
+      if (row[i] === 0) {
+        row[i] = 1
+      } else {
+        row[i] = 0
+      }
+    }
+  }
+  return A
+}

833/main.js

@@ -0,0 +1,33 @@
+/**
+ * @param {string} S
+ * @param {number[]} indexes
+ * @param {string[]} sources
+ * @param {string[]} targets
+ * @return {string}
+ */
+var findReplaceString = function (S, indexes, sources, targets) {
+  const maps = {}
+  for (let i = 0; i < indexes.length; i++) {
+    const idx = indexes[i]
+    const source = sources[i]
+    const target = targets[i]
+    if (S.indexOf(source, idx) === idx) {
+      maps[idx] = {
+        source,
+        target
+      }
+    }
+  }
+  let ans = ''
+  let i = 0
+  while (i < S.length) {
+    if (maps[i] != null) {
+      ans += maps[i].target
+      i += maps[i].source.length
+    } else {
+      ans += S[i]
+      i++
+    }
+  }
+  return ans
+}

835/main.js

@@ -0,0 +1,44 @@
+/**
+ * @param {number[][]} A
+ * @param {number[][]} B
+ * @return {number}
+ */
+var largestOverlap = function (A, B) {
+  function cnt (A, B) {
+    let ans = 0
+    for (let i = 0; i < rows; i++) {
+      for (let j = 0; j < cols; j++) {
+        if (A[i][j] === B[i][j] && A[i][j] === 1) {
+          ans += 1
+        }
+      }
+    }
+    return ans
+  }
+
+  function move (A, x, y) {
+    const next = Array.from(A, (_, i) => A[i].slice().fill(0))
+    for (let i = 0; i < rows; i++) {
+      for (let j = 0; j < cols; j++) {
+        const nx = x + i
+        const ny = y + j
+        if (nx >= rows || ny >= cols) {
+          continue
+        }
+        next[nx][ny] = A[i][j]
+      }
+    }
+    return next
+  }
+
+  const rows = A.length
+  const cols = A[0].length
+  let ans = 0
+  for (let i = 0; i < rows; i++) {
+    for (let j = 0; j < cols; j++) {
+      ans = Math.max(ans, cnt(move(A, i, j), B))
+      ans = Math.max(ans, cnt(move(B, i, j), A))
+    }
+  }
+  return ans
+}

README.md

@@ -247,6 +247,9 @@
 - [809 Expressive Words](./809/main.js)
 - [811 Subdomain Visit Count](./811/main.go)
 - [817 Linked List Components](./817/main.js)
+- [832 Flipping an Image](./832/main.js)
+- [833 Find And Replace in String](./833/main.js)
+- [835 Image Overlap](./835/main.js)
 
 *Q: What is `LZS`? It almost appears inside all files (like js, cpp)?*
 A: Briefly speaking, that is an environment variable defined in my System. For unix/linux, you can add a command `export LZS='true'` in `~/.bashrc` such that `process.env.LZS` evaluates to `true` rather than `undefined.`