[WEEK04-1] 추슬기

doitchuu/firstBadVersion.js

@@ -0,0 +1,36 @@
+/**
+ * Definition for isBadVersion()
+ * 
+ * @param {integer} version number
+ * @return {boolean} whether the version is bad
+ * isBadVersion = function(version) {
+ *     ...
+ * };
+ */
+
+/**
+ * @param {function} isBadVersion()
+ * @return {function}
+ */
+var solution = function(isBadVersion) {
+    /**
+     * @param {integer} n Total versions
+     * @return {integer} The first bad version
+     */
+    return function(n) {
+        let start = 1;
+        let end = n;
+
+        while (start < end) {
+            const middle = Math.floor((start + end) / 2);
+
+            if (isBadVersion(middle)) {
+                end = middle;
+            } else {
+                start = middle + 1;
+            }
+        }
+
+        return start;
+    };
+};

doitchuu/ransomNote.js

@@ -0,0 +1,26 @@
+/**
+ * @param {string} ransomNote
+ * @param {string} magazine
+ * @return {boolean}
+ */
+var canConstruct = function(ransomNote, magazine) {
+    const map = new Map();
+
+    for (let i = 0; i < ransomNote.length; i++) {
+        map.set(ransomNote[i], (map.get(ransomNote[i]) || 0) + 1);
+    }
+
+    for (let i = 0; i < magazine.length; i++) {
+        const value = map.get(magazine[i]);
+
+        if (value) {
+            if (value === 1) {
+                map.delete(magazine[i]);
+            } else {
+                map.set(magazine[i], map.get(magazine[i]) - 1);
+            }
+        }
+    }
+
+    return map.size === 0 ? true : false;
+};