习题目录
- 数组寻找最大值
- 个位和十位都不是7，并且只能是偶数
- 百钱白鸡
- 两个数组的比较
- 输入一个数，查找这个数在数组中的索引值
- 翻转数组
- 评委打分，计算最后分数
- 兔子出生
- 逢七必过
- Other
数组寻找最大值
public class array_exercise {
public static void main(String[] args) {
// //数组寻找最大值
// int[] arr = new int[]{12, 23, 43, 1, 23, 345};
// int max = arr[0];
// for (int i = 1; i < arr.length; i++) {
// if (arr[i] > max) {
// max = arr[i];
// }
// }
// System.out.println(max);
// //通过三目运算式输出最大值
// int[] arr = {1, 2, 3, 54, 65, 324, 6, 4636, 234, 534, 6};
// int max = arr[0];
// for (int i=1;i
// max = arr[i]>max ? arr[i] : max ;
// System.out.println(max);
//
// }
}
}
个位和十位都不是7，并且只能是偶数
public class ArraySummation {
public static void main(String[] args) {
int sum=0;
int[] arr;
int[] arr2 = new int[12];
arr = new int[]{68, 27, 95, 88, 171, 996, 51, 210};
for (int i = 0; i < arr.length; i++) {
int a = arr[i] % 10;//个位是7
int b = arr[i] / 10 % 10;//十位是7
// System.out.println(arr[i]);
if (a != 7 && b != 7 && arr[i] % 2 == 0) {
System.out.println("符合要求的数字："+arr[i]);
arr2[i]=arr[i];
}
}
for (int j=0;j
百钱白鸡
public class Buy_chicken_problem {
public static void main(String[] args) {
for (int x=1;x<100;x++){
for (int y=1;y<100;y++){
for (int z=1;z<100;z++){
if (x+y+z==100 && 5*x+3*y+z/3==100){
System.out.println("穷举法："+x+"t"+y+"t"+z);
}
}
}
}
}
}
两个数组的比较
public class CompareArrays {
public static void main(String[] args) {
int[] arr1 = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
int[] arr2 = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 78};
int[] arr3 = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
System.out.println(getCompareArrays(arr1, arr2));
}
public static boolean getCompareArrays(int[] arr1, int[] arr2) {
if (arr1.length != arr2.length) {
return false;
}
for (int i = 0; i < arr1.length; i++) {
if (arr1[i]!=arr2[i]){
return false;
}
}
return true;
}
}
输入一个数，查找这个数在数组中的索引值
import java.util.Scanner;
public class FindProblems {
public static void main(String[] args) {
int[] arr = new int[]{19, 28, 37, 46, 50};
System.out.println("Please enter a number:");
Scanner n = new Scanner(System.in);
int N = n.nextInt();
System.out.println(getIndex(arr,N));
}
//查找这个数是否为数组中的元素，如果不是返回-1，如果是的返回对应的索引
public static int getIndex(int arr[],int N){
int index = -1;
for (int i = 0; i < arr.length; i++) {
if (N == arr[i]) {
index=i;
break;
}
}
return index;
}
}
翻转数组
public class InvertArray {
public static void main(String[] args) {
int[] arr;
arr = new int[]{19, 28, 37, 46, 50};
InverArray(arr);
}
public static void InverArray(int arr[]) {
int[] arrtmp = new int[100];
for (int start = 0, end = arr.length - 1; start <= end; start++, end--) {
// System.out.println(arr[start]);
arrtmp[start] = arr[start];
arr[start] = arr[end];
arr[end]=arrtmp[start];
// int tmp = arr[start];
// arr[start] = arr[end];
// arr[end] = tmp;
}
System.out.print("[");
for (int i = 0; i < arr.length; i++)
if (i == arr.length-1) {
System.out.print(arr[i]);
}else {
System.out.print(arr[i]+",");
}
System.out.print("]");
}
}
评委打分，计算最后分数
import java.util.Scanner;
public class JudgesScore {
public static void main(String[] args) {
Scanner score = new Scanner(System.in);
int[] arr = new int[6];
int length=arr.length;
for (int i = 0; i < length; i++) {
System.out.println("Please rate the "+(i+1)+" first judge:");
int a = score.nextInt();
if (a > 0 && a < 100) {
arr[i] = a;
} else {
System.out.println("Erro");
length = arr.length+1;
}
}
System.out.println(getScore(arr));
}
// 根据要求去掉最大值和最小值求得平均分
public static int getScore(int arr[]) {
int max = arr[0], min = arr[0], score = 0, sum = 0;
for (int i = 0; i < arr.length; i++) {
if (max > arr[i]) {
max = arr[i];
return max;
}
if (min < arr[i]) {
min = arr[i];
return min;
}
sum += arr[i];
return sum;
}
score = (sum - max - min) / arr.length - 2;
return score;
}
}
兔子出生
public class rabbit_practice {
public static void main(String[] args) {
//关于兔子出生的案例
int[] rb = new int[20];
rb[0] = 1;
rb[1] = 1;
for (int i=2;i
逢七必过
public class Skip_seven {
public static void main(String[] args) {
getSeven();//缝七必过
}
//遇见7 或者是含有7或者是7的倍数则跳过
public static void getSeven() {
int a, b, c;
for (int i = 1; i < 100; i++) {
a = i % 10;
b = i / 10 % 10;
c = i % 7;
if (a == 7 || b == 7 || c == 0) {
System.out.println(i);
}
}
}
}
Other
public class method_study {
public static void main(String[] args) {
}
//数组最大值
public static int getarraryN(int[] ar) {
int max=ar[0];
for (int i=0;i max) {
max = ar[i];
}
}
System.out.println(max);
return max;
}
// 数组遍历
public static int getArrary() {
int[] arry = new int[]{11, 22, 33, 44, 55};
System.out.print("[");
for (int i = 0; i < arry.length; i++) {
if (i == arry.length - 1) {
System.out.print(arry[i]);
} else {
System.out.print(arry[i] + ",");
}
}
System.out.println("]");
return 0;
}
//方法的重载代码
public static boolean getint(int a, int b) {
System.out.println("int");
return a == b;
}
public static boolean getint(long a, long b) {
System.out.println("long");
return a == b;
}
public static boolean getint(short a, short b) {
System.out.println("short");
return a == b;
}
public static boolean getint(byte a, byte b) {
System.out.println("byte");
return a == b;
}
//给定方法判段ab哪一个更大
public static int getmax(int a, int b) {
if (a > b) {
return a;
} else {
return b;
}
}
//给定参数判断是否为偶数
public static boolean getEvenNumber(int a) {
if (a % 2 == 0) {
return true;
} else {
return false;
}
}
//获取两个数的最大值（有参）
public static void getMax(int a, int b) {
if (a > b) {
System.out.println(a);
} else {
System.out.println(b);
}
}
//获取两个数的最大值（无参）
public static void LargerNumber() {
Scanner n = new Scanner(System.in);
int a = n.nextInt();
int b = n.nextInt();
if (a > b) {
System.out.println(a);
} else {
System.out.println(b);
}
}
//水仙花数
public static void NarcissisticNumber() {
for (int i = 100; i < 1000; i++) {
int b = i / 100;
int s = i / 10 % 10;
int g = i % 10;
if (b * b * b + s * s * s + g * g * g == i) {
System.out.println(i);
}
}
// int count=0;
// for(int j=1;j<10;j++){
// for (int n=1;n<10;n++){
// for (int b=1;b<10;b++){
// if(n==j+1&&b==n+1){count++;System.out.println(""+j+n+b+n+j);}
//
// }
// }
// }
// System.out.println(count);
}
}
