Java输入输出(用于比赛)_java fastscanner-优快云博客

这篇博客探讨了在Java编程比赛中如何有效地处理输入输出。内容包括如何读取标准输入，进行数据处理，并将结果输出到标准输出，这对于参赛者优化算法性能至关重要。

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输入：

	public static class FastScanner {
		BufferedReader br;
		StringTokenizer st;

		public FastScanner(String s) {
			try {
				br = new BufferedReader(new FileReader(s));
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			}
		}

		public FastScanner() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String nextToken() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		public boolean EOF() {
			if (st != null && st.hasMoreTokens()) {
				return false;
			} else {
				String line = null;
				try {
					line = br.readLine();
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (line == null)
					return true;
				st = new StringTokenizer(line);
				return false;
			}
		}

		int nextInt() {
			return Integer.parseInt(nextToken());
		}

		long nextLong() {
			return Long.parseLong(nextToken());
		}

		double nextDouble() {
			return Double.parseDouble(nextToken());
		}
	}

输出：

		PrintWriter out = new PrintWriter(System.out);
		//最后要记得flush()
		out.flush();