solve no.657.There're 2 solutions.First one,use new Map().Second count horizontal(x),vertical(y).

Author: clingoram

javascript/index.js

@@ -1315,7 +1315,7 @@ var findAndReplacePattern = function(words, pattern) {
 };
 let word = ["abc","deq","mee","aqq","dkd","ccc"], pattern = "abb";
 // ["mee","aqq"]
-console.log(findAndReplacePattern(word,pattern));
+// console.log(findAndReplacePattern(word,pattern));
 
 /**
  * 657. Robot Return to Origin
@@ -1331,11 +1331,63 @@ var judgeCircle = function(moves) {
    * x(0),y(0)
    * u = d
    * r = l
+   * 
+   * 計算每個字母出現次數，r的出現次數 = l的出現次數; u 的出現次數 = d的出現次數
   */
+  // solution 1.
+  // TC:O(N)
+  // let direactionsCount = new Map();
+  // for(let i = 0;i < moves.length;++i) {
+  //   direactionsCount.has(moves[i]) ? direactionsCount.set(moves[i],direactionsCount.get(moves[i])+1) : direactionsCount.set(moves[i],1);
+  // }
+  // // 取得Map.get(key)對應value
+  // if(direactionsCount.get("U") === direactionsCount.get("D") && direactionsCount.get("R") === direactionsCount.get("L")){
+  //   return true;
+  // }
+  // return false;
+
+  // this solution?
+  // let direactionsObj = {};
+  // for(let i = 0;i < moves.length;++i) {
+  //   if(Object.hasOwn(direactionsObj, moves[i])){
+  //     direactionsObj[moves[i]] +=1;
+  //   }else{
+  //     direactionsObj[moves[i]] = 1;
+  //   }
+  // }
+  // console.log(direactionsObj)
 
+  // solution 2.
+  // TC: O(N)
+  // 計算x和y各自出現次數
+  // x = 水平(左右); y = 垂直(上下)
+  let x = 0,y = 0;
+  // 水平(x):
+  // L:x--; R:x++;
+  // 垂直(y):
+  // U:y++ ; D: y--
+  for(let i = 0;i < moves.length;++i) {
+    if(moves[i] === 'R'){
+      x++;
+    }else if(moves[i] === 'U'){
+      y++;
+    }else if(moves[i] === 'L'){
+      x--
+    }else if(moves[i] === 'D'){
+      y--;
+    }
+  }
+  return x === 0 && y === 0;
 
 };
 let moves = "UD";
-// Output: true
-// Explanation: The robot moves up once, and then down once. All moves have the same magnitude, so it ended up at the origin where it started. Therefore, we return true.
+/*
+Output: true
+Explanation: The robot moves up once, and then down once. All moves have the same magnitude, so it ended up at the origin where it started. Therefore, we return true.
+*/
+// let moves = "LL";
+/*
+Output: false
+Explanation: The robot moves left twice. It ends up two "moves" to the left of the origin. We return false because it is not at the origin at the end of its moves.
+*/
 console.log(judgeCircle(moves));