闰年判断
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); if((n % 4 == 0 && n % 100 != 0) || (n % 400 == 0)){ System.out.println("yes"); }else{ System.out.println("no"); } } }
01字串
public class Main { public static void main(String[] args) { for(int i = 0; i <= 1; i++){ for(int j = 0; j <= 1; j++){ for(int z = 0; z <= 1; z++){ for(int m = 0; m <= 1; m++){ for(int r = 0; r <= 1; r++){ System.out.printf("%s%s%s%s%s\n",i,j,z,m,r); } } } } } } }
字母图形
import java.util.Scanner; import static java.lang.Math.abs; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n1 = sc.nextInt(); int n2 = sc.nextInt(); String[] arr = {"A","B","C","D","E","F","G", "H","I","J","K","L","M","N","O","P", "Q","R","S","T","U","V","W","X","Y","Z" }; for(int i = 0; i < n1; i++){ for(int j = 0; j < n2; j++){ int k = abs(i-j); System.out.print(arr[k]); } System.out.println(); } } }
数列特征
import java.util.Arrays; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int[] arr = new int[n]; for(int i = 0; i < n; i++){ arr[i] = sc.nextInt(); } Arrays.sort(arr); System.out.println(arr[n-1]); System.out.println(arr[0]); int sum = 0; for (int value : arr) { sum += value; } System.out.println(sum); } }
查找整数
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int[] arr = new int[n]; for(int i = 0; i < n; i++){ arr[i] = sc.nextInt(); } int s = sc.nextInt(); System.out.println(find(arr, n, s)); } public static int find(int[] arr, int n, int s){ int index = -1; for(int i = 0; i < n; i++){ if(arr[i] == s){ index = i + 1; break; } } return index; } }
杨辉三角形
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int[][] arr = new int[n][n]; //存储数值 for(int i = 0; i < n; i++){ for(int j = 0; j <= i; j++){ //第一列和最后一列为0 if(j == 0 || j == i){ arr[i][j] = 1; }else{ arr[i][j] = arr[i-1][j] + arr[i-1][j-1]; } } } //打印 for(int i = 0; i < n; i++){ for(int j = 0; j <= i; j++){ System.out.print(arr[i][j] + " "); } System.out.println(); } } }
特殊的数字
public class Main{ public static void main(String[] args) { for(int i = 1; i <= 9; i++){ //有0! for(int j = 0; j <= 9; j++){ for(int z = 0; z <= 9; z++){ int index = i * 100 + j * 10 + z; if(index == i * i * i + j * j * j + z * z *z){ System.out.println(index); } } } } } }
回文数
public class Main { public static void main(String[] args) { //除以10可以提取前面,余10可以提取后面 for(int i = 1000; i <= 9999; i++){ if((i / 1000 == i % 10) && (i / 100 % 10 == i % 100 / 10)){ System.out.println(i); } } } }
特殊回文数
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); //除以10可以提取前面,余10可以提取后面 //求一个三位数的各个位数 : n / 100 % 10 n / 10 % 10 n / 1 % 10 for(int i = 10000; i <= 999999; i++){ if(i < 100000){ if((i / 10000 % 10 == i % 10) && (i / 1000 % 10 == i / 10 % 10)){ if((i / 10000 % 10+ i / 1000 % 10 + i / 100 % 10 + i / 10 % 10 + i % 10) == n){ System.out.println(i); } } } if(i >= 100000){ if((i / 100000 % 10 == i % 10) && (i / 10000 % 10 == i / 10 % 10) && (i / 1000 % 10 == i / 100 % 10)){ if((i / 100000 % 10 + i / 10000 % 10 + i / 1000 % 10 + i /100 % 10 + i / 10 % 10 + i % 10) == n){ System.out.println(i); } } } } } }
数列排列
import java.util.Arrays; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int[] arr = new int[n]; for(int i = 0; i < n; i++){ arr[i] = sc.nextInt(); } Arrays.sort(arr); for(int a : arr){ System.out.print(a + " "); } } }