[leet] valid sudoku (mid)

Author: hyeonbinHur

허현빈/8주차/Valid Sudoku.js

@@ -0,0 +1,53 @@
+var isValidSudoku = function (board) {
+  for (let i = 0; i < 9; i++) {
+    const set = new Set();
+    for (let j = 0; j < 9; j++) {
+      if (board[i][j] !== ".") {
+        if (set.has(board[i][j])) {
+          return false;
+        } else {
+          set.add(board[i][j]);
+        }
+      }
+    }
+
+    const set2 = new Set();
+    for (let j = 0; j < 9; j++) {
+      if (board[j][i] !== ".") {
+        if (set2.has(board[j][i])) {
+          return false;
+        } else {
+          set2.add(board[j][i]);
+        }
+      }
+    }
+  }
+
+  for (let i = 1; i <= 3; i++) {
+    for (let j = 1; j <= 3; j++) {
+      const set = new Set();
+      for (let k = 1; k <= 3; k++) {
+        const val1 = board[i * 3 - k][j * 3 - 3];
+        const val2 = board[i * 3 - k][j * 3 - 2];
+        const val3 = board[i * 3 - k][j * 3 - 1];
+        if (val1 !== "." && !set.has(val1)) {
+          set.add(val1);
+        } else if (set.has(val1)) {
+          return false;
+        }
+        if (val2 !== "." && !set.has(val2)) {
+          set.add(val2);
+        } else if (set.has(val2)) {
+          return false;
+        }
+
+        if (val3 !== "." && !set.has(val3)) {
+          set.add(val3);
+        } else if (set.has(val3)) {
+          return false;
+        }
+      }
+    }
+  }
+  return true;
+};

허현빈/8주차/isSubsequence.js

@@ -0,0 +1,14 @@
+/**
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+var isSubsequence = function (s, t) {
+  let idx = 0;
+  for (let i = 0; i < t.length; i++) {
+    if (s[idx] === t[i]) {
+      idx++;
+    }
+  }
+  return idx === s.length;
+};