CT_281

BOJ/Java/src/S4/Boj_11502_세개의소수문제.java

@@ -0,0 +1,84 @@
+package S4;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+
+public class Boj_11502_세개의소수문제 {
+    private static StringBuilder answer;
+    private static int[] selected, primes;
+    private static int target;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        answer = new StringBuilder();
+        primes = make_Prime(1000);
+        selected = new int[3];
+
+        int T = Integer.parseInt(br.readLine());
+
+        for (int t = 0; t < T; t++) {
+            target = Integer.parseInt(br.readLine());
+            if (!combination(0, 0, 0)) {
+                answer.append(0).append('\n');
+            }
+        }
+
+        bw.write(answer.toString());
+        bw.flush();
+    }
+
+    private static boolean combination(int cnt, int start, int sum) {
+        if (cnt == 3) {
+            if (sum == target) {
+                for (int num : selected) {
+                    answer.append(num).append(' ');
+                }
+                answer.append('\n');
+                return true;
+            }
+            return false;
+        }
+
+        for (int i = start; i < primes.length; i++) {
+            selected[cnt] = primes[i];
+            if (sum + primes[i] > target) {
+                return false;
+            } else if (combination(cnt + 1, i, sum + primes[i])) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private static int[] make_Prime(int max) {
+        boolean[] primes = new boolean[max];
+        int cnt = 0;
+
+        for (int i = 2; i < max; i++) {
+            if (!primes[i]) {
+                cnt++;
+                for (int j = 2; i * j < max; j++) {
+                    primes[i * j] = true;
+                }
+            }
+        }
+
+        int[] result = new int[cnt];
+        int index = 2;
+
+        for (int i = 0; i < cnt; i++) {
+            while (primes[index]) {
+                index++;
+            }
+            result[i] = index++;
+        }
+
+        return result;
+    }
+}