.

Ssafy_test/src/BOJ/silver1/BOJ_10844.java

@@ -0,0 +1,49 @@
+package BOJ.silver1;
+
+import java.io.*;
+
+public class BOJ_10844 {
+	static int n;
+	static int[][] dp;
+
+	public static int DP(int dept, int num) {
+
+		if(dp[dept][num] != 0) {
+			return dp[dept][num]%1000000000;
+		}
+
+		if(num == 0) {
+			dp[dept][num] = DP(dept-1, num+1)%1000000000;
+		}else if(num == 9) {
+			dp[dept][num] = DP(dept-1, num-1)%1000000000;
+		}else{
+			dp[dept][num] = DP(dept-1, num-1)%1000000000 + DP(dept-1, num+1)%1000000000;
+		}
+
+		return dp[dept][num]%1000000000;
+	}
+
+	public static void main(String[] args) throws IOException{
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+		n = Integer.parseInt(br.readLine());
+		dp = new int[n][10];
+
+		//초기화
+		for(int i = 0; i<10; i++) {
+			dp[0][i] = 1;
+		}
+
+		int ans = 0;
+
+		for(int i = 1; i<10; i++) {
+			ans += DP(n-1,i);
+			ans%=1000000000;
+		}
+		bw.write(ans + "\n");
+		bw.flush();
+		bw.close();
+		br.close();
+	}
+}

Ssafy_test/src/BOJ/silver1/BOJ_11057.java

@@ -0,0 +1,47 @@
+package BOJ.silver1;
+
+import java.io.*;
+import java.util.*;
+
+public class BOJ_11057 {
+	static int num;
+	static int[][] dp;
+
+	public static int DP(int dept, int num) {
+		if(dp[dept][num] != 0) {
+			return dp[dept][num];
+		}
+
+		for(int i = num; i<10; i++) {
+			dp[dept][num] += DP(dept-1,i)%10007;
+			dp[dept][num] %= 10007; 
+		}
+
+		return dp[dept][num]%10007;
+	}
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+		num = Integer.parseInt(br.readLine());
+		dp = new int[num][10]; //dept, n
+
+		int ans = 0;
+
+		//초기화
+		for(int i = 0; i<10; i++) {
+			dp[0][i] = 1;
+		}
+
+		for(int i = 0; i<10; i++) {
+			ans += DP(num-1, i);
+			ans%=10007;
+		}
+
+		bw.write(ans + "\n");
+		bw.flush();
+		bw.close();
+		br.close();
+	}
+}

Ssafy_test/src/BOJ/silver1/BOJ_2156.java

@@ -23,27 +23,11 @@ public static void main(String[] args) throws IOException {
 		if(num>=2) {
 			dp[num-2] = ll[num-2] + ll[num-1]; //초기화
 			for(int i = num-3; i>=0; i--) {
-				//dp[i+3] 부터 max
-				int a = 0;
-				for(int j = i+3; j< num; j++) {
-					a = Math.max(a, dp[j]);
-				}
-
-				//dp[i+2] 부터 max
-				int b = 0;
-				for(int j = i+2; j< num; j++) {
-					b = Math.max(b, dp[j]);
-				}
-
-				dp[i] = ll[i] + Math.max(ll[i+1] + a, b);
+				dp[i] = Math.max(ll[i]+ ll[i+1] + dp[i+3], Math.max(dp[i+1],ll[i] + dp[i+2]));
 			}
 		}
 
-		for(int i = 0; i<num; i++) {
-			ans = Math.max(ans, dp[i]);
-		}
-
-		bw.write(ans + "\n");
+		bw.write(dp[0] + "\n");
 		bw.flush();
 		br.close();
 		bw.close();

Ssafy_test/src/BOJ/silver1/BOJ_9465.java

@@ -0,0 +1,52 @@
+package BOJ.silver1;
+
+import java.io.*;
+import java.util.*;
+
+public class BOJ_9465 {
+	public static void main(String[] args) throws IOException{
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+		int num = Integer.parseInt(br.readLine());
+
+		for(int z = 0; z<num; z++) {
+			int n = Integer.parseInt(br.readLine());
+			int[][] ll = new int[2][n];
+			int[][] dp = new int[2][n];
+
+			int ans = 0;
+
+			for(int i = 0; i<2; i++) {
+				StringTokenizer st = new StringTokenizer(br.readLine());
+				for(int j = 0; j<n; j++) {
+					ll[i][j] = Integer.parseInt(st.nextToken());
+				}
+			}
+			//초기화
+			dp[0][n-1] = ll[0][n-1];
+			dp[1][n-1] = ll[1][n-1];
+
+			if(n>=2) {
+				dp[0][n-2] = ll[0][n-2] + ll[1][n-1];
+				dp[1][n-2] = ll[1][n-2] + ll[0][n-1];
+
+				for(int j = n-3; j>=0; j--) {
+					for(int i = 0; i<2; i++) {
+						int m = Math.max(dp[0][j+2], dp[1][j+2]);
+
+						if(i == 0) {
+							dp[i][j] = Math.max(ll[i][j] + Math.max(dp[1][j+1], m), dp[0][j+1]);
+						}else { //i == 1
+							dp[i][j] = Math.max(ll[i][j] + Math.max(dp[0][j+1], m), dp[1][j+1]);
+						}
+					}
+				}
+			}
+			bw.write(Math.max(dp[1][0], dp[0][0]) + "\n");
+		}
+		bw.flush();
+		br.close();
+		bw.close();
+	}
+}