week 28

junghyeon/보석쇼핑.js

@@ -0,0 +1,30 @@
+function solution(gems) {
+    let answer = [1, gems.length];
+    let left = 0, right = 0;
+    let target = new Set(gems).size
+    const map = new Map()
+    map.set(gems[0], 1)
+
+    //right이 범위를 초과할 때까지 반복
+    while(right < gems.length) {
+        if(target == map.size) {
+            // 1. left++ (빈도수-1, 빈도수 0이 되면 Map에서 삭제)        
+            // 2. right - left가 answer 보다 더 짧은 구간이라면 answer에 재할당
+            if(right - left < answer[1] - answer[0]) {
+                answer[0] = left +1;
+                answer[1] = right+1;
+            }
+            map.set(gems[left], map.get(gems[left]) - 1)
+            if(map.get(gems[left]) == 0) {
+                map.delete(gems[left])
+            }
+            left++;
+        } else {
+            // 조건이 만족될 때까지 right++ (빈도수 +1)            
+            right++;
+            map.set(gems[right], map.get(gems[right]) ? map.get(gems[right]) +1 : 1)   
+        }
+    }
+
+    return answer;
+}

junghyeon/징검다리건너기.js

@@ -0,0 +1,31 @@
+const isCross = (stones, mid, k) => {
+    let count = 0;
+
+    for(const stone of stones) {
+        if(stone-mid <= 0) {
+            count++;    
+            if(count === k) return false
+        } else {
+            count =0;   
+        }
+    }
+    return true
+}
+
+
+function solution(stones, k) {
+    let min = 1
+    let max = 200000000
+    console.log(min, max)
+    while (min <= max) {
+        let mid = Math.floor((min + max) / 2)
+        if(isCross(stones, mid, k)) {
+            min = mid + 1
+            console.log("min",min)
+        } else {
+            max = mid -1
+            console.log("max",max)
+        }
+    }
+    return min
+}