[이예슬] 02.03 집합/그래프 문제 제출

solutions/yesul/0203/[문제33]간단한유니온파인드알고리즘구현하기.js

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+function solution(k, operations) {
+    const parent = Array.from({ length: k }, (_, index) => index);
+
+    function find(x) {
+        if (parent[x] === x) {
+            return x;
+        }
+
+        return parent[x] = find(parent[x]);
+    }
+
+    function union(x, y) {
+        const rootX = find(x);
+        const rootY = find(y);
+
+        if (rootX !== rootY) {
+            if (rootY < rootX) {
+                parent[rootX] = rootY;
+            } else {
+                parent[rootY] = rootX;
+            }
+        }
+    }
+
+    for (const [operation, ...args] of operations) {
+        if (operation === 'u') {
+            union(...args);
+        } else if (operation === 'f') {
+            find(...args);
+        }
+    }
+
+    // 집합의 개수 세기
+    return parent.filter((val, idx) => val === idx).length;
+
+}
+
+console.log(solution(3, [['u', 0, 1], ['u', 1, 2], ['f', 2]])) // 1
+console.log(solution(4, [['u', 0, 1], ['u', 2, 3], ['f', 0]])) // 2

solutions/yesul/0203/[문제34]폰켓몬.js

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+function solution(nums) {
+    const max = nums.length / 2;
+    const types = new Set(nums);
+
+    return Math.min(types.size, max);
+}
+
+console.log(solution([3, 1, 2, 3])) // 2
+console.log(solution([3, 3, 3, 2, 2, 4])) // 3
+console.log(solution([3, 3, 3, 2, 2, 2])) // 2

solutions/yesul/0203/[문제35]섬연결하기.js

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+function solution(n, costs) {
+    const parent = Array.from({ length: n }, (_, i) => i);
+
+    function find(x) {
+        if (parent[x] === x) {
+            return x;
+        }
+
+        return parent[x] = find(parent[x]);
+    }
+
+    function union(x, y) {
+        const rootX = find(x);
+        const rootY = find(y);
+        if (rootX !== rootY) {
+            parent[rootY] = rootX;
+            return true;
+        }
+        return false;
+
+    }
+
+    // 가장 적은 다리 건설 비용
+    costs.sort((a, b) => a[2] - b[2]);
+
+    let total = 0;
+
+    for (const [from, to, cost] of costs) {
+        if (union(from, to)) {
+            total += cost;
+        }
+    }
+
+    return total;
+}