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  1. /*
  2.  * To change this license header, choose License Headers in Project Properties.
  3.  * To change this template file, choose Tools | Templates
  4.  * and open the template in the editor.
  5.  */
  6.  
  7.  
  8. /**
  9.  *
  10.  * @author RYMA
  11.  */
  12. import java.io.BufferedOutputStream;
  13. import java.io.IOException;
  14. import java.io.InputStream;
  15. import java.io.PrintWriter;
  16. import java.util.InputMismatchException;
  17. import java.util.*;
  18.  
  19. public class Main {
  20. 	public static void main(String[] args) {
  21. 		new Main();
  22. 	}
  23.         public int min(int a,int b){
  24.             return (a>b)? b:a;
  25.         }
  26.         public int min(int a,int b,int c){
  27.             int x = min(a,b);
  28.             return min(x,c);
  29.         }
  30. 	public Main() {
  31. 		FasterScanner sc = new FasterScanner(System.in);
  32. 		FastPrinter printer = new FastPrinter();
  33.                 int N = sc.nextInt();
  34.                 int a[] = new int[N];
  35.                 for(int i=0;i<N;++i){
  36.                     a[i]=sc.nextInt();
  37.                 }
  38.                 if(N<=3){
  39.                     Arrays.sort(a);
  40.                     System.out.println(a[0]);
  41.                 }
  42.                 else{
  43.                     int b[] = new int[N];
  44.                     b[0]=a[0];
  45.                     b[1]=a[1];
  46.                     b[2]=a[2];
  47.                     for(int i=3;i<N;++i){
  48.                         int x = b[i-1]>b[i-2] ? b[i-2]:b[i-1];
  49.                         int y = b[i-3]>x ? x : b[i-3];
  50.                         b[i]= y+a[i];
  51.                     }
  52.                     int x = b[N-1]>b[N-2] ? b[N-2]:b[N-1];
  53.                     int y = b[N-3]>x ? x : b[N-3];
  54.                     System.out.println(y);
  55.                 }
  56.                 printer.close();
  57. 		sc.close();
  58. 	}
  59.  
  60. 	public class FasterScanner {
  61. 		private InputStream mIs;
  62. 		private byte[] buf = new byte[1024];
  63. 		private int curChar;
  64. 		private int numChars;
  65.  
  66. 		public FasterScanner() {
  67. 			this(System.in);
  68. 		}
  69.  
  70. 		public FasterScanner(InputStream is) {
  71. 			mIs = is;
  72. 		}
  73.  
  74. 		public int read() {
  75. 			if (numChars == -1)
  76. 				throw new InputMismatchException();
  77. 			if (curChar >= numChars) {
  78. 				curChar = 0;
  79. 				try {
  80. 					numChars = mIs.read(buf);
  81. 				} catch (IOException e) {
  82. 					throw new InputMismatchException();
  83. 				}
  84. 				if (numChars <= 0)
  85. 					return -1;
  86. 			}
  87. 			return buf[curChar++];
  88. 		}
  89.  
  90. 		public String nextLine() {
  91. 			int c = read();
  92. 			while (isSpaceChar(c))
  93. 				c = read();
  94. 			StringBuilder res = new StringBuilder();
  95. 			do {
  96. 				res.appendCodePoint(c);
  97. 				c = read();
  98. 			} while (!isEndOfLine(c));
  99. 			return res.toString();
  100. 		}
  101.  
  102. 		public String nextString() {
  103. 			int c = read();
  104. 			while (isSpaceChar(c))
  105. 				c = read();
  106. 			StringBuilder res = new StringBuilder();
  107. 			do {
  108. 				res.appendCodePoint(c);
  109. 				c = read();
  110. 			} while (!isSpaceChar(c));
  111. 			return res.toString();
  112. 		}
  113.  
  114. 		public long nextLong() {
  115. 			int c = read();
  116. 			while (isSpaceChar(c))
  117. 				c = read();
  118. 			int sgn = 1;
  119. 			if (c == '-') {
  120. 				sgn = -1;
  121. 				c = read();
  122. 			}
  123. 			long res = 0;
  124. 			do {
  125. 				if (c < '0' || c > '9')
  126. 					throw new InputMismatchException();
  127. 				res *= 10;
  128. 				res += c - '0';
  129. 				c = read();
  130. 			} while (!isSpaceChar(c));
  131. 			return res * sgn;
  132. 		}
  133.  
  134. 		public int nextInt() {
  135. 			int c = read();
  136. 			while (isSpaceChar(c))
  137. 				c = read();
  138. 			int sgn = 1;
  139. 			if (c == '-') {
  140. 				sgn = -1;
  141. 				c = read();
  142. 			}
  143. 			int res = 0;
  144. 			do {
  145. 				if (c < '0' || c > '9')
  146. 					throw new InputMismatchException();
  147. 				res *= 10;
  148. 				res += c - '0';
  149. 				c = read();
  150. 			} while (!isSpaceChar(c));
  151. 			return res * sgn;
  152. 		}
  153.  
  154. 		public boolean isSpaceChar(int c) {
  155. 			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  156. 		}
  157.  
  158. 		public boolean isEndOfLine(int c) {
  159. 			return c == '\n' || c == '\r' || c == -1;
  160. 		}
  161.  
  162. 		public void close() {
  163. 			try {
  164. 				mIs.close();
  165. 			} catch (IOException e) {
  166. 				e.printStackTrace();
  167. 			}
  168. 		}
  169. 	}
  170.  
  171. 	class FastPrinter {
  172. 		PrintWriter writer;
  173.  
  174. 		/**
  175. 		 * Initialize the writer.
  176. 		 */
  177. 		public FastPrinter() {
  178. 			writer = new PrintWriter(new BufferedOutputStream(System.out));
  179. 		}
  180.  
  181. 		/**
  182. 		 * Print the given String and add a newline.
  183. 		 * 
  184. 		 * @param string
  185. 		 *            The given String.
  186. 		 */
  187. 		public void println(String string) {
  188. 			writer.println(string);
  189. 		}
  190.  
  191. 		/**
  192. 		 * Print the given String.
  193. 		 * 
  194. 		 * @param string
  195. 		 *            The given String.
  196. 		 */
  197. 		public void print(String string) {
  198. 			writer.print(string);
  199. 		}
  200.  
  201. 		public void close() {
  202. 			writer.close();
  203. 		}
  204. 	}
  205. }
Success #stdin #stdout 0.04s 4386816KB
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https://ideone.com/lVtsdx
language:
Java (HotSpot 12)
created:
6 years ago
visibility:
public

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