「題目代碼」P1029～P1033（Java）

1029 C基礎-求解方程

import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class Main
{
    public static void main(String args[])
    {
        for(int i=100;i<=999;++i)
        {// 這特麼不需要排除相同項
            int j=1333-i; if(/* i>j || */j<100 || j>=1000) continue;
            int ig=i%10,is=(i/10)%10,ib=i/100,
                jg=j%10,js=(j/10)%10,jb=j/100;

            if(ig==jb && ib==jg && is==js)
            {
                System.out.println(i+"+"+j+"="+1333);
            }
        }
    }
}

1030 C基礎-選擇半徑

import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class Main
{
    public static void main(String args[])
    {
        Scanner cin=new Scanner(System.in);
        for(int i=1;i<=10;++i)
        {
            double s=i*3.14159*i;
            if(s>=40.0 && s<=90.0)
            {
                System.out.printf("r=%d area=%.2f\n",i,s);
            }
        }
    }
}

1031 C基礎-選擇排序

/* Insertion Sort - P1031
 * The algorithm divides the input list into two parts: the sublist of items    
 * already sorted, which is built up from left to right at the front (left) of
 * the list, and the sublist of items remaining to be sorted that occupy the
 * rest of the list. Initially, the sorted sublist is empty and the unsorted
 * sublist is the entire input list. The algorithm proceeds by finding the
 * smallest (or largest, depending on sorting order) element in the unsorted
 * sublist, exchanging (swapping) it with the leftmost unsorted element
 * (putting it in sorted order), and moving the sublist boundaries one element
 * to the right.
 */
import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class Main
{
    public static void main(String args[])
    {
        Scanner cin=new Scanner(System.in);
        int[] arr=new int[15];
        for(int i=1;i<=10;++i)
        {
            arr[i]=cin.nextInt();
        }
        for(int i=1;i<=10;++i)
        {
            int minId=i;
            for(int j=i;j<=10;++j)
                if(arr[minId]>arr[j])
                    minId=j;
            swap(arr,minId,i);
        }
        for(int i=1;i<=10;++i)
            System.out.println(arr[i]);
    }
    // a mainstream implementation due to limitation of Java itself.
    public static void swap(int[] arr, int a, int b) {  
        int temp = arr[a];  
        arr[a] = arr[b];  
        arr[b] = temp;  
    }
}

1032 C基礎-局部求和

import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class Main
{
    public static void main(String args[])
    {
        Scanner cin=new Scanner(System.in);
        int[] arr=new int[25];
        for(int i=1;i<=20;++i)
        {
            arr[i]=cin.nextInt();
        }
        for(int i=1;i<=20;++i)
        {
            for(int j=1;j<=20;++j)
            {
                if(i==j) continue;
                if(arr[i]%arr[j]==0) {System.out.println(arr[i]); break;}
            }
        }
    }
}

1033 C基礎-對角線和

import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class Main
{
    public static void main(String args[])
    {
        Scanner cin=new Scanner(System.in);
        int[][] arr=new int[5][5];
        for(int i=1;i<=3;++i)
        {
            for(int j=1;j<=3;++j)
                arr[i][j]=cin.nextInt();
        }
        System.out.println((int)(arr[1][1]+arr[2][2]+arr[3][3]));
    }
}