java-数组—acwing

题目一：数组替换

737. 数组替换 - AcWing题库

代码 

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int[] q = new int[10];
        for(int i = 0; i < 10; i ++) 
            q[i] = sc.nextInt();
        
        for(int i = 0; i < 10; i ++) 
            if(q[i] <= 0) 
                q[i] = 1;
        
        for(int i = 0; i < 10; i ++) 
            System.out.printf("X[%d] = %d\n",i,q[i]);
    }
}

题目二：数组填充

738. 数组填充 - AcWing题库

代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int[] q = new int[10];
        
        q[0] = sc.nextInt();
        for(int i = 1; i < 10; i ++) {
            q[i] = q[i-1]*2;
        }
        
        for(int i = 0; i < 10; i ++) 
            System.out.printf("N[%d] = %d\n",i,q[i]);
    }
}

 题目三：数组选择

739. 数组选择 - AcWing题库

 代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        double[] q = new double[100];
        for(int i = 0; i < 100; i ++) {
            q[i] = sc.nextDouble();
        }
        
        for(int i = 0; i < 100; i ++) 
            if(q[i]<=10) 
                System.out.printf("A[%d] = %.1f\n",i,q[i]);
    }
}

题目四：数组中的行

743. 数组中的行 - AcWing题库

代码 （数据存储与计算同步）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        String s = sc.next();
        
        double ans = 0;
        double[][] q = new double[12][12];
        for(int i = 0; i < 12; i ++) {
            for(int j = 0; j < 12; j ++) {
                q[i][j] = sc.nextDouble();
                if(i == l) {
                    ans += q[i][j];
                    if(j==11 && "M".equals(s)) ans /= 12;
                }
            }
        }
        System.out.printf("%.1f\n",ans);
    }
}

代码2（存储后进行数据处理）

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        String s = sc.next();
        
        double ans = 0;
        double[][] q = new double[12][12];
        for(int i = 0; i < 12; i ++) 
            for(int j = 0; j < 12; j ++) 
                q[i][j] = sc.nextDouble();
        
        for(double x : q[l]) ans += x;
        if("M".equals(s)) ans /= 12;
        
        System.out.printf("%.1f\n",ans);
    }
}

题目五：数组的右上半部分

745. 数组的右上半部分 - AcWing题库

代码 

import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        String op = sc.next();
        double[][] q = new double[12][12];
        double ans = 0; int num = 0;
        for(int i = 0; i < 12; i ++) {
            for(int j = 0; j < 12; j ++) {
                q[i][j] = sc.nextDouble();
                
                if(i < j) {
                    ans += q[i][j];
                    num ++;
                }
            }
        }
        if("M".equals(op)) ans /= num;
        System.out.printf("%.1f\n",ans);
    }
}

题目六：数组的左上半部分

747. 数组的左上半部分 - AcWing题库

代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        String op = sc.next();
        double[][] q = new double[12][12];
        double ans = 0; int num = 0;
        for(int i = 0; i < 12; i ++) {
            for(int j = 0; j < 12; j ++) {
                q[i][j] = sc.nextDouble();
                if(j < 11-i) {
                    ans += q[i][j];
                    num ++;
                }
            }
        }
        if("M".equals(op)) ans /= num;
        System.out.printf("%.1f\n",ans);
    }
}

题目七：数组的上方区域

749. 数组的上方区域 - AcWing题库

代码

import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String op = sc.next();
        double ans = 0; int num = 0;
        double[][] q = new double[12][12];
        for(int i = 0; i < 12; i ++) {
            for(int j = 0; j < 12; j ++) {
                q[i][j] = sc.nextDouble();
                if(j>i && j<11-i) {
                    ans += q[i][j];
                    num ++;
                }
            }
        }
        if("M".equals(op)) ans /= num;
        System.out.printf("%.1f\n",ans);
    }
}

题目八：数组的左方区域

751. 数组的左方区域 - AcWing题库

代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        double ans = 0; int num = 0;
        double[][] q = new double[12][12];
        String op = sc.next();
        
        for(int i = 0; i < 12; i ++) {
            for(int j = 0; j < 12; j ++) {
                q[i][j] = sc.nextDouble();
                if(j<i && j<11-i) {
                    ans += q[i][j];
                    num ++;
                }
            }
        }
        if("M".equals(op)) ans /= num;
        System.out.printf("%.1f\n",ans);
    }
}

题目九：平方矩阵1

753. 平方矩阵 I - AcWing题库

代码

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        while (n > 0) {
            int[][] q = new int[n][n];
            for(int i = 0; i < n; i ++) {
                for(int j = 0; j < n; j ++) {
                    // 上下 和 左右 收缩的最小值
                    int x = Math.min(i+1, n-i);
                    int y = Math.min(j+1, n-j);
                    int z = Math.min(x,y);
                    System.out.printf("%d ",z);
                }
                System.out.println("");
            }
            n = sc.nextInt();
            System.out.println("");
        }
    }
}