1 本题是水题，题目要求你求最大值、最小值，建议你用Arrays.sort函数进行排序，最大值、最小值就可以确定了
1 import java.util.Arrays; 2 import java.util.Scanner; 3 4 public class paone { 5 public static void main(String[] args) { 6 int [] aa = new int[5]; 7 double sum = 0.0; 8 Scanner input =new Scanner(System.in); 9 for (int i = 0; i <5 ; i++) { 10 aa[i] = input.nextInt(); 11 sum += aa[i]; 12 } 13 Arrays.sort(aa); 14 for (int a : aa) 15 System.out.print(a+" "); 16 System.out.println(); 17 System.out.println("最小值:"+aa[0]); 18 System.out.println("最大值:"+aa[4]); 19 System.out.println("平均值:"+sum/5); 20 } 21 }
2 本题建议用swtich函数进行统计1-6的整数，每次产生一个随机数，就进行+1，switch中进行统计数目的大小建议用素组来定义。
1 import java.util.Random; 2 3 public class potwo { 4 public static void main(String[] args) { 5 Random r = new Random(); 6 int [] a =new int[1000]; 7 int [] b =new int[6]; 8 int count = 0; 9 for (int i = 0; i < 1000; i++) { 10 a[i] = r.nextInt(6)+1; 11 switch (a[i]){ 12 case 1: 13 b[0]++; 14 break; 15 case 2: 16 b[1]++; 17 break; 18 case 3: 19 b[2]++; 20 break; 21 case 4: 22 b[3]++; 23 break; 24 case 5: 25 b[4]++; 26 break; 27 case 6: 28 b[5]++; 29 break; 30 } 31 } 32 for (int A : a){ 33 count++; 34 System.out.print(A+" "); 35 if (count % 10 == 0) 36 System.out.println(); 37 } 38 System.out.println("1的个数为"+b[0]); 39 System.out.println("2的个数为"+b[1]); 40 System.out.println("3的个数为"+b[2]); 41 System.out.println("4的个数为"+b[3]); 42 System.out.println("5的个数为"+b[4]); 43 System.out.println("6的个数为"+b[5]); 44 } 45 }
3 本题水题，还是用sort函数进行排序，直接找到最小元素
1 import java.util.Arrays; 2 import java.util.Scanner; 3 4 public class pothree { 5 public static void main(String[] args) { 6 double [] arrays = new double[5]; 7 Scanner input = new Scanner(System.in); 8 for (int i = 0; i <5 ; i++) { 9 arrays[i]=input.nextDouble(); 10 } 11 System.out.println("这个元素最小值是:"+min(arrays)); 12 } 13 public static double min(double[] array){ 14 Arrays.sort(array); 15 return array[0]; 16 } 17 }
4 本题水题根据题目意思写即可，注意交换位置如何交换 a ^= b; b ^= a; a ^= b;
1 import java.util.Scanner; 2 3 public class pofour { 4 public static void main(String[] args) { 5 int [] aa = new int[10]; 6 Scanner input =new Scanner(System.in); 7 for (int i = 0; i < 10 ; i++) { 8 aa[i] = input.nextInt(); 9 } 10 System.out.println("排序前的元素:"); 11 for (int A : aa) 12 System.out.print(A+" "); 13 System.out.println(); 14 for (int i = 0; i < 4 ; i++) { 15 aa[i] ^= aa[9-i]; 16 aa[9-i] ^= aa[i]; 17 aa[i] ^= aa[9-i]; 18 } 19 System.out.println("交换后的元素:"); 20 for (int A : aa) 21 System.out.print(A+" "); 22 } 23 }
5 理解题目意思即可
1 import java.util.Scanner; 2 3 public class pofive { 4 public static void main(String[] args) { 5 int [] aa = new int[8]; 6 Scanner input =new Scanner(System.in); 7 for (int i = 0; i < 8; i++) { 8 aa[i]=input.nextInt(); 9 } 10 System.out.println("选择排序前:"); 11 for (int A : aa) 12 System.out.print(A+" "); 13 System.out.println(); 14 for (int i = 0; i < 7; i++) { 15 int k = i; 16 for (int j = k+1; j < 8 ; j++) { 17 if (aa[j] < aa[k]) 18 k = j; 19 } 20 21 if (i!=k) { 22 aa[i] ^= aa[k]; 23 aa[k] ^= aa[i]; 24 aa[i] ^= aa[k]; 25 } 26 /* for (int A : aa) 27 System.out.print(A+" "); 28 System.out.println();*/ 29 } 30 System.out.println("选择排序后:"); 31 for (int A : aa) 32 System.out.print(A+" "); 33 } 34 }
6 根据题目意思，把Fibonacci数列意思理解即可
1 public class posix { 2 public int [] aa = new int[20]; 3 public static void main(String[] args) { 4 posix posix =new posix(); 5 int i,count=0; 6 for (i = 0; i < 20; i++) { 7 System.out.print(posix.fic(i)+" "); 8 count++; 9 if (count % 10 ==0) 10 System.out.println(); 11 } 12 13 14 } 15 public int fic(int n){ 16 if (n==0) 17 return aa[n]=1; 18 if (n==1) 19 return aa[n]=1; 20 else 21 return fic(n-2)+fic(n-1); 22 } 23 }
7 本题有点坑，你写的可能只是一种结果，因为你定义a、b两个数组，两个数组的长度有三种可能 a>b;a=b;a<b;三种可能，注意即可
1 import java.util.Scanner; 2 3 public class Poseven { 4 public static void main(String[] args) { 5 //int [] aa ={1,2,3,4,15}; 6 //int [] bb ={4,5,6,7}; 7 8 int a,b; 9 Scanner input = new Scanner(System.in); 10 11 12 13 System.out.print("请输入第一个数组的元素个数："); 14 a=input.nextInt(); 15 System.out.print("请输入第二个数组的元素个数："); 16 b=input.nextInt(); 17 int []aa=new int[a]; 18 int []bb=new int[b]; 19 System.out.println("请输入第一个数组的元素："); 20 for (int i = 0; i < a; i++) { 21 aa[i] = input.nextInt(); 22 } 23 System.out.println("请输入第二个数组的元素："); 24 for (int i = 0; i < b; i++) { 25 bb[i] = input.nextInt(); 26 } 27 System.out.println("加之前两个数组分别为:"); 28 for (int AA : aa) 29 System.out.print(AA+" "); 30 System.out.println(); 31 for (int BB : bb) 32 System.out.print(BB+" "); 33 System.out.println(); 34 System.out.println("相加后数组为:"); 35 Poseven poseven =new Poseven(); 36 int []abs= poseven.sumAraay(aa,bb); 37 for (int ABS : abs) 38 System.out.print(ABS+" "); 39 40 41 } 42 public static int[] sumAraay(int [] a,int [] b){ 43 int max,min; 44 max = a.length >= b.length ? a.length:b.length; 45 min = a.length < b.length ? a.length:b.length; 46 int leng1=a.length,leng2=b.length; 47 int sum []=new int[max]; 48 for (int i = 0; i < min; i++) { 49 sum[i] = a[i]+b[i]; 50 leng1--; 51 leng2--; 52 } 53 for (int j = min; j < max; j++) { 54 if (leng1==0) 55 sum[j] = b[j]; 56 else 57 sum[j] = a[j]; 58 } 59 /* for (int SUM : sum) 60 System.out.print(SUM+" "); 61 System.out.println();*/ 62 return sum; 63 64 } 65 66 }
8 定义一个可以放下这两个素组大小的素组，记录一个数组存完后，这个素组的下标即可
1 import java.util.Arrays; 2 3 public class Poeight { 4 public static void main(String[] args) { 5 Poeight poeight =new Poeight(); 6 int [] aa = {1,10,3,4}; 7 int [] bb = {4,5,6,7,8}; 8 System.out.println("和成前的数组分别为:"); 9 for (int AA : aa) 10 System.out.print(AA+" "); 11 System.out.println(); 12 for (int BB : bb) 13 System.out.print(BB+" "); 14 System.out.println(); 15 System.out.println("合成后的数组为:"); 16 int [] merge=poeight.arrayMerge(aa,bb); 17 for (int MERGE : merge) 18 System.out.print(MERGE+" "); 19 System.out.println(); 20 21 } 22 public static int [] arrayMerge(int [] a,int [] b){ 23 int sum=a.length+b.length; 24 int [] suml = new int[sum]; 25 int min = a.length < b.length ? a.length:b.length; 26 int max = a.length >= b.length ? a.length:b.length; 27 for (int i = 0; i < min ; i++) { 28 if (a.length < b.length) 29 suml[i] = a[i]; 30 else 31 suml[i] = b[i]; 32 } 33 for (int i = min; i < sum; i++) { 34 if (a.length>b.length) 35 suml[i] = a[i-b.length]; 36 else 37 suml[i] = b[i-a.length]; 38 } 39 Arrays.sort(suml); 40 return suml; 41 } 42 }
9 根据题目意思，直接求解即可
1 import java.util.Scanner; 2 3 public class Ponine { 4 public static void main(String[] args) { 5 double [] aa = new double[3]; 6 double [] bb = new double[3]; 7 Scanner input = new Scanner(System.in); 8 System.out.print("请依次输入a,b,c的值:"); 9 aa[0] = input.nextDouble(); 10 aa[1] = input.nextDouble(); 11 aa[2] = input.nextDouble(); 12 double x1 =( -aa[1]+Math.sqrt(Math.pow(aa[1],2)-4*aa[0]*aa[2]))/2*aa[0]; 13 double x2 =( -aa[1]-Math.sqrt(Math.pow(aa[1],2)-4*aa[0]*aa[2]))/2*aa[0]; 14 bb[0]=x1; 15 bb[1]=x2; 16 17 System.out.println("根的个数为"+ solveQuadratic(aa,bb)); 18 19 } 20 public static int solveQuadratic(double [] eqn, double [] roots){ 21 int solve=-1; 22 if(Math.pow(eqn[1],2)-4*eqn[0]*eqn[2]==0) 23 solve=1; 24 if(Math.pow(eqn[1],2)-4*eqn[0]*eqn[2] > 0) 25 solve=2; 26 return solve; 27 } 28 }
10 本题有个小技巧，我用的是“置0法”，把不符合要求的全部置0，2是素数，所以我们从下标为1的开始筛选，这个方法有点坑，因为你这样筛选可能会把本身给筛选掉，就需要错位筛选，比如筛选2的倍数，我们从3开始筛选，依次类推，因为求的是2~100的素数，所以因子只可能到50，定义循环的次数即可
1 public class Poten { 2 public static void main(String[] args) { 3 int a[] = new int[100]; 4 //int b[] =new int[99]; 5 int i,k,j,cout=0; 6 for (i = 0; i < 99 ; i++) { 7 a[i] = i+2; 8 } 9 for (int A : a) 10 System.out.print(A+" "); 11 System.out.println(); 12 /* System.out.println(); 13 k=0; 14 System.out.println(a.length); 15 for (i=0;i<a.length;i++) { 16 if (a[i] % 2 != 0) { 17 b[k] = a[i]; 18 k++; 19 } 20 } 21 for (i=0;i<b.length;i++) 22 System.out.print(b[i]+" ");*/ 23 // 把每次结果都输出来显示。 24 for (j = 2; j <=50 ; j++) { 25 for (k = j-1 ; k<a.length ; k++) { 26 if (a[k] % j == 0) 27 a[k]=0; 28 } 29 for (int A : a) 30 System.out.print(A+" "); 31 System.out.println(); 32 } 33 34 for (i=0;i<a.length;i++){ 35 if (a[i]!=0) 36 System.out.print(a[i]+" "); 37 } 38 // a[i] != '\0' 39 //System.out.println(cout); 40 } 41 }
11 根据题目意思理解即可
1 import java.util.Arrays; 2 3 public class Poeleven { 4 public static void main(String[] args) { 5 int [] a={1,2,3,4}; 6 int [] b={1,2,3,4}; 7 8 System.out.println( equals(a,b)); 9 // System.out.println(a.equals(b)); 10 } 11 public static boolean equals (int [] list1,int [] list2){ 12 // 定义count的原因是把满足题目条件的结果进行加一 13 int count=0; 14 if(Arrays.equals(list1,list2)){ 15 for (int i = 0; i <list1.length ; i++) { 16 if(list1[i]==list2[i]) 17 count++; 18 } 19 } 20 // 满足条件的结果与数组长度相等则满足 21 if (count==list1.length) 22 return true; 23 else 24 return false; 25 } 26 27 }
12 本题用的 较简单的方法与第十题基本想法一致，每次循环一遍就把那个数“置0”
1 public class Potwleven { 2 3 public static void main(String[] args) { 4 int j=0,i=0; 5 int a[]={1,2,3,4,5,6,7,8,9,10,11,12}; 6 //int t= s(a); 7 // while循环的条件就是数组里面不为18的数大于1 8 while (s(a)>1){ 9 // 因为是12个数，则用%12来进行循环 10 if (a[i%12]!=18) 11 j++; 12 if (j % 5 == 0) 13 a[i%12]=18; 14 i++; 15 } 16 // System.out.println(j); 17 for (int k = 0; k <a.length ; k++) { 18 if (a[k]!=18) 19 System.out.println(a[k]); 20 } 21 } 22 public static int s(int a[]){ 23 int count=0; 24 for (int i = 0; i < a.length; i++) { 25 if (a[i]!=18) 26 count++; 27 } 28 return count; 29 } 30 }
13 本题的选牌次数纯属运气，因为有随机，根据题目意思定义一个二维数组来存放牌
1 import java.util.Random; 2 3 public class threeteen { 4 public static void main(String[] args) { 5 int [][]desk = new int[4][13]; 6 int count=1; 7 // 用来存放选牌的次数 8 int cu=0; 9 boolean flag =true; 10 for (int i = 0; i <4 ; i++) { 11 for (int j = 0; j < 13; j++) { 12 desk[i][j]=count; 13 count++; 14 } 15 count=1; 16 } 17 18 Random random =new Random(); 19 while (flag) { 20 cu++; 21 int r1 = random.nextInt(4); 22 int r2 = random.nextInt(13); 23 int a = desk[r1][r2]; 24 int b = desk[r1][r2]; 25 int c = desk[r1][r2]; 26 int d = desk[r1][r2]; 27 if (a+b+c+d==24) 28 flag=false; 29 30 } 31 System.out.println(cu); 32 } 33 34 /* public static void main(String[] args) { 35 int[] sum = new int[52]; 36 int[] a = new int[4]; 37 boolean flag = true; 38 for (int i = 0; i < 52; i++) { 39 sum[i] = i % 13 + 1; 40 } 41 for (int i = 0; i < sum.length; i++) { 42 System.out.print(sum[i] + " "); 43 } 44 System.out.println(); 45 46 Random random = new Random(); 47 int r = random.nextInt(52); 48 int n = sum.length; 49 int cu = 0; 50 while (flag) { 51 for (int i = 0; i < 4; i++) { 52 a[i] = sum[r]; 53 for (int j = r; j < n - 1; j++) { 54 sum[j] = sum[j + 1]; 55 } 56 n--; 57 for (int j = 0; j < n; j++) { 58 System.out.print(sum[j] + " "); 59 } 60 System.out.println(); 61 } 62 63 System.out.println(); 64 if (a[0]+a[1]+a[2]+a[3]==24) 65 flag=false; 66 }*/ 67 68 69 }
14 本题就是求因子，每次求得的因子就让他进栈，知道最后一次进栈，最后再出栈，即可
1 import java.util.Scanner; 2 3 public class Pofourteen { 4 private int[]elements; 5 private int size=0; 6 public static final int DEFAULT_CAPACITY = 10; 7 8 public Pofourteen(){ 9 this(DEFAULT_CAPACITY); 10 } 11 public Pofourteen(int capacity){ 12 elements = new int[capacity]; 13 } 14 //进栈 15 public void push(int value){ 16 if(size >= elements.length){ 17 int []temp = new int[elements.length*2]; 18 System.arraycopy(elements,0,temp,0,elements.length); 19 elements = temp; 20 } 21 elements[size++]=value; 22 } 23 //出栈 24 public int pop() { 25 return elements[--size]; 26 } 27 28 public int peek() { 29 return elements[size--]; 30 } 31 // 栈是否为空 32 public boolean empty() { 33 return size == 0; 34 } 35 36 public int getSize() { 37 return size; 38 } 39 40 41 public static void main(String[] args) { 42 Scanner input = new Scanner(System.in); 43 int number = input.nextInt(); 44 Pofourteen stack = new Pofourteen(); 45 Pofourteen stack1 =new Pofourteen(); 46 int ans=0; 47 int[] a = new int[20]; 48 while (number != 1) { 49 for (int i = 2; i <= number; i++) { 50 if (number % i == 0) { 51 // a[ans] = i; 52 stack.push(i); 53 ans++; 54 number /= i; 55 break; 56 } 57 } 58 } 59 while (!stack.empty()) { 60 stack1.push(stack.pop()); 61 // System.out.print(stack1.pop() + " "); 62 } 63 //System.out.println(); 64 while (!stack1.empty()) { 65 // stack1.push(stack.pop()); 66 System.out.print(stack1.pop() + " "); 67 } 68 } 69 }
15 注意转置是什么意思，就是行列里面的元素互换
1 public class Pofifteen { 2 public static void main(String[] args) { 3 int [][]A= {{1,3,5},{-3,6,0},{13,-5,7},{-2,19,25}}; 4 int [][]B={{0,-1,2},{7,-1,6},{-6,13,2},{12,-8,-13}}; 5 System.out.println("A+B矩阵"); 6 jia(A,B); 7 System.out.println("A-B矩阵"); 8 jian(A,B); 9 // System.out.println(A[0].length); 10 // System.out.println(A.length); 11 System.out.println("*********************"); 12 System.out.println("A的转置"); 13 zhuan(A); 14 } 15 public static void jia(int [][]a,int [][]b){ 16 int [][] add= new int[4][3]; 17 for (int i = 0; i < 4; i++) { 18 for (int j = 0; j < 3; j++) { 19 add [i][j] = a[i][j]+b[i][j]; 20 System.out.print(add [i][j]+" "); 21 } 22 System.out.println(); 23 } 24 } 25 public static void jian(int [][]a,int [][]b){ 26 int [][] add= new int[4][3]; 27 for (int i = 0; i < 4; i++) { 28 for (int j = 0; j < 3; j++) { 29 add [i][j] = a[i][j]-b[i][j]; 30 System.out.print(add [i][j]+" "); 31 } 32 System.out.println(); 33 } 34 } 35 public static void zhuan(int [][]a){ 36 int [][]AA=new int[3][4]; 37 for (int i = 0; i < a[0].length; i++) { 38 for (int j = 0; j < a.length; j++) { 39 AA[i][j]=a[j][i]; 40 } 41 } 42 for (int i = 0; i < a[0].length; i++) { 43 for (int j = 0; j < a.length; j++) { 44 System.out.print(AA[i][j]+" "); 45 } 46 System.out.println(); 47 } 48 } 49 }
16 把二维素组的下标存入数组即可
1 import java.util.Scanner; 2 3 public class Posixteen { 4 public static int a1,a2; 5 public static void main(String[] args) { 6 System.out.print("请输入数组的行数和列数:"); 7 Scanner input = new Scanner(System.in); 8 9 a1 = input.nextInt(); 10 a2 =input.nextInt(); 11 double [][]A=new double[a1][a2]; 12 for (int i = 0; i <a1 ; i++) { 13 for (int j = 0; j <a2 ; j++) { 14 A[i][j] = input.nextDouble(); 15 } 16 } 17 int C[]=locateLargest(A); 18 System.out.println("最大数的位置是:"+"("+C[0]+","+C[1]+")"); 19 } 20 public static int[] locateLargest(double [][] a){ 21 int n=0; 22 int m=0; 23 int c[]=new int[2]; 24 for (int i = 0; i <a1 ; i++) { 25 for (int j = 0; j <a2 ; j++) { 26 // a[i][j] = input.nextDouble(); 27 if (a[i][j]>a[n][m]) { 28 c[0] = i; 29 c[1] = j; 30 n=i; 31 m=j; 32 } 33 } 34 } 35 return c; 36 } 37 }
17 本题水题，但是有点意思，根据题目的意思写即可
1 import java.util.Scanner; 2 3 public class Potwelve { 4 /* public static void main(String[] args) { 5 Scanner input = new Scanner(System.in); 6 int num = input.nextInt(); 7 int count = 1; 8 int n=0,m=num/2; 9 int temp1=0,temp2=0; 10 int [][]A = new int[num][num]; 11 for (int i = 0; i <num*num; i++) { 12 13 // System.out.println(n+" "+m); 14 15 // if (A[n][m]==0){ 16 // A[n][m]=count; 17 if (A[n][m]!=0) { 18 n=++temp1; 19 m=temp2; 20 } 21 A[n][m]=count; 22 23 // System.out.println(n+" "+m+" "+A[n][m]); 24 count++; 25 temp1 = n; 26 temp2 =m; 27 n--; 28 m++; 29 if (n==-1) 30 n=num-1; 31 if (m==num) 32 m=0; 33 // } 34 } 35 for (int i = 0; i <num; i++) { 36 for (int j = 0; j <num; j++) { 37 System.out.print(A[i][j]+" "); 38 } 39 System.out.println(); 40 } 41 }*/ 42 public static void main(String[] args) { 43 Scanner input =new Scanner(System.in); 44 int num = input.nextInt(); 45 int [][]A=new int[num][num]; 46 47 int x=0,y=num/2; 48 for (int i = 1; i <=num*num ; i++) { 49 50 if (A[x][y]!=0) { 51 //A[x][y] = i; 52 x=(x+2)%num; 53 // y=(y+1)%num; 54 // 保存原来位置的y 55 y=(y+num-1)%num; 56 } 57 A[x][y]=i; 58 x=(x+num-1)%num; 59 y=(y+1)%num; 60 } 61 for (int i = 0; i < num; i++) { 62 for (int j = 0; j < num; j++) { 63 System.out.print(A[i][j]+" "); 64 } 65 System.out.println(); 66 } 67 } 68 }