「题目代码」P1029～P1033（Java）

1029 C基础-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)

        {// 这特么不需要排除相同项

            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基础-选择半径

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基础-选择排序

/* 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基础-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基础-对角线和

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]));

    }

}