Java/C++输入输出特定格式模板总结

System.out.printf("%-5d",arr[i]);

System.out.printf("%.3f",num[i]);

printf("%-5d", a[i]);

printf("MEDIA = %.3lf",a[i]);

public class Solution {
    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 4, 5};
        // 输出每个数字占五个空格
        for (int i = 0 ; i < arr.length; i++) {
            System.out.printf("%-5d",arr[i]);
        }
        System.out.println();
        double[] num = {1.0, 2.0, 3.0, 4.0, 5.0};
        // 输出每个数字带有3个小数点
        for (int i = 0; i < num.length; i++) {
            System.out.printf("%.3f",num[i]);
        }
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
public class Main {
    public static void main(String[] args) throws IOException {
        Read read = new Read();
        // 接收单个数字
        int n = read.nextInt();
        int m = read.nextInt();
        int[][] arr = new int[n][m];
        // 接收n*m的数字类型的数组
        for (int i = 0; i < n; i++) {
            for (int j = 0 ; j < m; j++) {
                arr[i][j] = read.nextInt();
            }
        }
        // 接收一行字符串
        String s = read.getStringLine();
        // 输出一个数字后面加空格不换行
        System.out.print(n + " ");
        // 输出一个字符串并换行
        System.out.println(s);
    }
}
class Read {
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    StreamTokenizer st = new StreamTokenizer(new InputStreamReader(System.in));
    public int nextInt() throws IOException {
        st.nextToken();
        return (int) st.nval;
    }
    public double nextDouble() throws IOException {
        st.nextToken();
        return st.nval;
    }
    public String nextString() throws IOException {
        st.nextToken();
        return st.sval;
    }
    public String getStringLine() throws IOException {
        return reader.readLine();
    }
}