class ArrayWork {
/*
* 二维数组的复习!
*
* 2014年4月2日 21:45:50
*
*
*
**/
public static void main(String[] args){
int [] arr = {2,4,4,3,64,85,84,3,24,89,4};
System.out.println("-------------------------------");
//找出整型数组的是2倍数的数有几个
int count = 0;
for (int i = 0;i<arr.length ;i++ ){
if (arr[i] % 2 == 0){
count++;
}
}
System.out.println("数组中2的倍数: " + count + "个");
System.out.println("-------------------------------");
boolean bo = false;
for (int i = 0;i<arr.length ;i++ ){
if (arr[i] % 2 == 0){
bo = true;
}
}
if (bo){
System.out.println("存在!");
}else{
System.out.println("不存在!");
}
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
int star = arr[0];
for (int i = 0;i<arr.length-1;i++ ){
arr[i]=arr[i+1];
}
arr[arr.length-1]=star;
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
boolean boo = false;
for (int i = 0;i<arr.length ;i++ ){
if (arr[i] % 5 == 0){
System.out.println(arr[i]);
boo = true;
break;
}
}
if (boo==false){
System.out.println("不存在!");
}
System.out.println("-------------------------------");
//改变数组元素值，将一个整型数组里下标是偶数的元素都乘3
for (int i= 0;i<arr.length ;i++ ){
if (i%2==0){
arr[i]=arr[i]*3;
}
}
for (int i = 0;i<arr.length ;i++){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
//改变数组元素值，将一个整型数组里下标是奇数的元素都加3
for (int i= 0;i<arr.length ;i++ ){
if (i%2!=0){
arr[i]=arr[i]+3;
}
}
for (int i = 0;i<arr.length ;i++){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
//一个整型数组，有10个元素，打印出低于数组元素平均值的元素
int brr [] = {2,3,4,8,6,5,4,1,32,5};
int sun = 0;
for (int i = 0;i<brr.length ;i++ ){
sun += brr[i];
}
for (int i = 0;i<brr.length ;i++ ){
if (brr[i] < sun / brr.length){
System.out.print(brr[i] + " , ");
}
}
System.out.println();
System.out.println("-------------------------------");
//将数组中第一个元素移到最后数组末尾,其余数据依次往前平移一个位置。
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
int star2 = arr[0];
for (int i = 0;i<arr.length-1;i++ ){
arr[i]=arr[i+1];
}
arr[arr.length-1]=star2;
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
boolean bos = false;
for (int i = 0;i<arr.length ;i++ ){
if (arr[i] % 2 == 0){
bos = true;
}
}
if (bos){
System.out.println("存在!");
}else{
System.out.println("不存在!");
}
System.out.println("-------------------------------");
//一个整型数组，找出最大数所在位置
int big = arr[0];
int count0 = -1;
for (int i = 0;i<arr.length ;i++ ){
if (arr[0]<arr[i]){
arr[0]= arr[i];
count = i;
}
}
System.out.println("max下标: "+ count);
System.out.println("-------------------------------");
//一个整型数组，找出最小数所在位置，并将它与第一个数对调位置
//int crr [] = {5,4,5,6,1,3,2,4,8,85,3,4};
int start = arr[0];
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
int count1 = -1;
for (int i = 0;i<arr.length ;i++ ){
if (arr[0]>arr[i]){
arr[0]= arr[i];
count1 = i;
}
}
arr[count1] = start;
for (int i = 0;i<arr.length ;i++ ){
System.out.print(arr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
//查找数组中是否有等于 5 这个元素，有则返回这个元素在数组中的位置；没有，则返回 -1
int crr [] = {5,4,5,6,1,3,2,4,8,85,3,4};
int vart = -1;
for (int i = 0;i<crr.length ;i++){
if (crr[i]==5){
vart = i;
}
}
System.out.println(vart);
System.out.println("-------------------------------");
//输出数组的前n的值，n是一个变量
int suru = 200;
for (int i = 0;i<arr.length ;i++ ){
if (arr[i]<suru){
System.out.print(arr[i] + " , ");
}
}
System.out.println();
System.out.println("-------------------------------");
//删除数组中下标值是k的元素
int drr []={5,2,2,4,5,6};
int sd = 3;
for (int i = sd; i<drr.length-1;i++ ){
drr[i] = drr[i+1];
}
for (int i = 0;i<drr.length-1 ;i++ ){
System.out.print(drr[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
//定义一个整型数组，将一个数插在数组元素的末尾形成新的数组。输出新数组
int err [] = {5,2,2,4,5,6,324,23};
int frr [] = new int [err.length+1];
for (int i = 0;i<err.length ;i++ ){
frr[i]= err[i];
}
frr[frr.length-1] = suru;
for (int i = 0;i<frr.length ;i++ ){
System.out.print(frr[i]+" ,");
}
System.out.println();
System.out.println("-------------------------------");
//定义两个数组，将这两个数组合并形成新的数组，打印新数组
int grr []={2,1,5,6};
int hrr []={3,5,6,7,4};
int irr []=new int [grr.length+hrr.length];
for (int i = 0;i<grr.length ;i++ ){
irr[i]=grr[i];
}
for (int i = 0;i<hrr.length ;i++ ){
irr[grr.length+i]=hrr[i];
}
for (int i = 0;i<irr.length ;i++ ){
System.out.print(irr[i]+" ,");
}
System.out.println();
System.out.println("-------------------------------");
//16.定于1001班一个数组，里面存放大家的英语成绩，
// (1)统计不及格人数，并打印他们的分数，
// (2)统计成绩在全班平均分及平均分之上的学生人数，并打印他们的分数；
// (3)统计各分数段的学生人数及所占的百分比。分数段(0到30,30到60，60到80,80到90,90到100)
int jrr [] = {84,92,15,38,79,94,68,15,37,87,95,48,68,75,90,80};
int count2 = 0;
int count3 = 0;
int sum = 0;
for (int i = 0; i<jrr.length; i++){
sum += jrr[i];
if (jrr[i]<60){
System.out.print(jrr[i]+" , ");
count2 ++;
}
}
System.out.println("一共: "+ count2 +" 人");
System.out.println("平均分: "+sum/jrr.length);
System.out.println("下面是高于平均分的分数");
for (int i = 0;i<jrr.length ;i++ ){
if (jrr[i]>=sum/jrr.length){
System.out.print(jrr[i]+" , ");
count3++;
}
}
System.out.println();
System.out.println("高于平均分的人数有: "+ count3+" 人");
double g1 = 0;//90到100
double g2 = 0;//80到90
double g3 = 0;//60到80
double g4 = 0;//30到60
double g5 = 0;//0到30
for (int i = 0;i<jrr.length ;i++ ){
if (90<=jrr[i] && jrr[i]<=100){
g1++;
}else if (80<=jrr[i] && jrr[i]<90){
g2++;
}else if (60<=jrr[i] && jrr[i]<80){
g3++;
}else if (30<=jrr[i] && jrr[i]<60){
g4++;
}else if (0<=jrr[i] && jrr[i]<30){
g5++;
}
}
double dou1 = (g1/jrr.length)*100 ;
double dou2 = (g2/jrr.length)*100 ;
double dou3 = (g3/jrr.length)*100 ;
double dou4 = (g4/jrr.length)*100 ;
double dou5 = (g5/jrr.length)*100 ;
System.out.println("90到100 : "+g1 +" 人, 占百分比: "+ dou1+ "%");
System.out.println("90到100 : "+g2 +" 人, 占百分比: "+ dou2+ "%");
System.out.println("90到100 : "+g3 +" 人, 占百分比: "+ dou3+ "%");
System.out.println("90到100 : "+g4 +" 人, 占百分比: "+ dou4+ "%");
System.out.println("90到100 : "+g5 +" 人, 占百分比: "+ dou5+ "%");
System.out.println("-------------------------------");
// 数组
int tab[]={10,15,20,25,30,35,40,45,50,55} ;
int tabl = 30;
// 设计一个程序
// 比如输入30，要输出4，输入10要输出0，输入55要输出9，也就是tab的下标
for (int i = 0;i<tab.length ;i++ ){
if (tabl == tab[i]){
System.out.println(i);
}
}
System.out.println("-------------------------------");
//统计整型数组中的偶数个数
int tabe[]={10,15,20,25,30,34,40,45,50,55} ;
int count5 =0;
for (int i = 0; i<tabe.length; i++){
if (tabe[i]%2==0){
count5++;
}
}
System.out.println(count5 );
System.out.println("-------------------------------");
//输出数组中的元素 ，每3个元素一行
int taba[]={10,15,20,25,30,34,40,45,50,55} ;
int count6 =0;
for (int i = 0; i<taba.length; i++){
if (count6 % 3 == 0){
System.out.println();
}
System.out.print(taba[i]+" , ");
count6++;
}
System.out.println();
System.out.println("-------------------------------");
//计算整型数组a中的最大值及其所在的下标。
int tabs[]={10,15,20,25,55,30,34,40,45,50} ;
int count7 =tabs[0];
int count8 = -1;
for (int i = 0; i<tabs.length; i++){
if (count7 < tabs[i]){
count7 = tabs[i];
count8 = i;
}
}
System.out.println("最大值: "+count7 + " 下标: "+count8);
System.out.println("-------------------------------");
//定义一个字符串数组，把数组中的每个元素相加后输出
String dasf [] = {"h","e","l","l","o","w","o","r","d"};
for (int i = 0;i<dasf.length ;i++ ){
System.out.print(dasf[i]);
}
System.out.println();
System.out.println("-------------------------------");
//定义一个字符串数组，将其倒序输出\
String hello [] = {"h","e","l","l","o","w","o","r","d"};
for (int i = hello.length-1;i>=0 ;i-- ){
System.out.print(hello[i]);
}
System.out.println();
System.out.println("-------------------------------");
//有一个字符串数组 ，将数组中每个元素倒转，如 var x=new Array("a","b","c","d") 倒
// 转后x数组变成了("d","c","b","a")
String hello1 [] = {"h","e","l","l","o","w","o","r","d"};
String hello2 [] = new String[hello1.length];
int jsss = 0;
for (int i = hello.length-1;i>=0 ;i-- ){
hello2[jsss] = hello1[i];
jsss++;
}
for (int i = 0;i<hello2.length ;i++ ){
System.out.print(hello2[i]);
}
System.out.println();
System.out.println("-------------------------------");
//有一个字符串数组，分别统计其相同元素的个数并输出 如数组
//("a","b","a","d","b","b") 则输出a 2个 b 3个 d 一个（本题属于高难度题目）
String string []= {"a","b","a","d","b","b"};
int coun1 = 0;
int coun2 = 0;
int coun3 = 0;
for (int i = 0;i<string.length ;i++ ){
if (string[i].equals("a")){
coun1 ++;
}else if (string[i].equals("b")){
coun2 ++;
}else if (string[i].equals("d")){
coun3 ++;
}
}
System.out.println("a: "+ coun1 + " b: "+coun2 + " d: "+coun3);
System.out.println("-------------------------------");
//有两个长度相同的字符串数组，判断这两个数组中的对应元素是否完全相同，如果完全相
// 同则输出"呵呵，我爱死你了，怎么搞得跟我一样"，如果有不相同
// 则把那些不相同的元素打印出来 如("a","b","c")和("a","b","d") 则 打印 第3个元素
// 不相同 c与d
String str1 []= {"a","b","a","d","b","b"};
String str2 []= {"a","b","a","2","b","b"};
int co1 = 0;
for (int i = 0;i<str1.length ;i++ ){
if (str1[i].equals(str2[i])){
co1++;
}else {
System.out.println("第"+ (i+1) +"个元素不相同"+str1[i]+"与"+str2[i]);
break;
}
}
if (co1 == str1.length){
System.out.println("呵呵，我爱死你了，怎么搞得跟我一样");
}
System.out.println("-------------------------------");
// 两个字符串数组合并，重复的元素去掉，如("a","b","c")和("a","b","d")合并后的数组
// 为("a","b","c","d")(高难度)
String st1 []= {"a","b","c"};
String st2 []= {"a","b","d"};
String st3 []= new String [4];
for (int i = 0;i<st1.length ;i++ ){
st3[i] = st1[i];
}
for (int i = 0;i<st2.length ;i++ ){
if (st3[i].equals(st2[i])){
}else {
st3[st1.length] = st2[i];
}
}
for (int i = 0;i<st3.length ;i++ ){
System.out.print(st3[i]+" , ");
}
System.out.println();
System.out.println("-------------------------------");
int Int[]={15,20,25,55,30,34,10,40,45,50} ;
int max_1=Int[0];
int min_1=Int[0];
for (int i = 0;i<Int.length ;i++ ){
if (max_1<Int[i]){
max_1= Int[i];
}
if (min_1>Int[i]){
min_1=Int[i];
}
}
System.out.println("sum:" + (min_1 + max_1));
System.out.println("-------------------------------");
//有一个整型数组，对数组元素进行排序，从大到小输出 （高难度，属于后面要讲的数组排
//序内容【（比较交换法、选择法、冒泡法）】，能用你们的方法做出来固然好，做不 出来
//别把脑想坏了）
int Intger[]={15,20,25,55,30,34,10,40,45,50} ;
int ssa = Intger[0];
for (int i = 0;i<Intger.length ;i++ ){
for (int j = 0;j<Intger.length ;j++ ){
if (Intger[i]<Intger[j]){
ssa = Intger[j];
Intger[j] = Intger[i];
Intger[i] = ssa;
}
}
}
for (int i = 0;i<Intger.length ;i++ ){
System.out.print(Intger[i]+",");
}
System.out.println();
System.out.println("-------------------------------");
int fblx [] = new int[20];
fblx[0] = 1;
fblx[1] = 1;
for (int i = 2;i<fblx.length ;i++ ){
fblx[i]=fblx[i-1]+fblx[i-2];
}
for (int i = 0;i<fblx.length ;i++ ){
System.out.print(fblx[i]+" ,");
}
System.out.println();
System.out.println("-------------------------------");
//给定一个数据元素，要求根据这个元素把数组里的该元素删除 如var x="a";有数组 var
//cc=new Array("a","b","c"),则删除元素a后数组变成了("b","c")(有一定难度)
String []cc={"a","b","c"};
String []cc2=new String [cc.length-1];
int catr = 0;
for (int i = 0;i<cc.length ;i++ ){
if (cc[i].equals("a")){
}
}
for (int i= catr;i<cc.length-1 ;i++ ){
cc[i]=cc[i+1];
}
for (int i = 0;i<cc2.length ;i++ ){
cc2[i]=cc[i];
}
for (int i = 0;i<cc2.length ;i++ ){
System.out.print(cc2[i]+" ,");
}
System.out.println();
System.out.println("-------------------------------");
//将10个数放入到数组，然后再进行从小到大排序后输出。
int Intge[]={15,20,25,55,30,34,10,40,45,50} ;
int sa = Intge[0];
for (int i = 0;i<Intge.length ;i++ ){
for (int j = 0;j<Intge.length ;j++ ){
if (Intge[i]<Intge[j]){
sa = Intge[j];
Intge[j] = Intge[i];
Intge[i] = sa;
}
}
}
for (int i = 0;i<Intge.length ;i++ ){
System.out.print(Intge[i]+",");
}
System.out.println();
System.out.println("-------------------------------");
//将一个数组逆序输出。有20个数字
int Intg[]={15,20,25,55,30,34,10,40,45,50,15,20,25,55,30,34,10,40,45,50} ;
int seee = Intg[0];
for (int i = 0;i<Intg.length ;i++ ){
for (int j = 0;j<Intg.length ;j++ ){
if (Intg[i]>Intg[j]){
seee = Intg[j];
Intg[j] = Intg[i];
Intg[i] = seee;
}
}
}
for (int i = 0;i<Intg.length ;i++ ){
System.out.print(Intg[i]+",");
}
System.out.println();
System.out.println("-------------------------------");
//通过输入框输入数组，提示请输入第x个数字，当输入的-1为结束。最后输出这个数组的数据。
int Inttr[]={15,20,25,55,30,34,10,40,45,50,15,20,25,55,30,34,10,40,45,50} ;
int sdff = -1;
for (int i = 0;i<Inttr.length ;i++ ){
if (i==sdff){
System.out.println(Inttr[i]);
}else if (i==-1){
System.out.println("结束");
break;
}
}
for (int i = 0;i<Inttr.length ;i++ ){
System.out.print(Inttr[i]+" ,");
}
System.out.println();
System.out.println("-------------------------------");
//有一个数组a[2,5,9,2,6,3,1,2,5,6,7,8,4,0]，统计这个数字不相同的数字有多少个，它
//们相同的个数是多少。
int atery [] = {2,5,9,2,6,3,1,2,5,6,7,8,4,0};
int xt = 0;
int bt = 0;
for (int i = 0;i<atery.length ;i++ ){
for (int j = 0;j<atery.length ;j++){
if (atery[i]==atery[j]){
xt++;
}else {
bt++;
}
}
}
System.out.println("相同: "+xt/2+"不同: "+bt/12);
System.out.println("-------------------------------");
//有两个数组a[1,2,6,4,3,7,8,4,5,7],b[12,45,1,2,5,2,6,8,9],同时存在这两个数据的数
//字有哪些，请输出。
int szji1 [] = {1,2,6,4,3,7,8,4,5,7};
int szji2 [] = {12,45,1,2,5,2,6,8,9};
for (int i = 0;i<szji1.length ;i++ ){
for (int j = 0;j<szji2.length ;j++){
if (szji1[i]==szji2[j]){
System.out.println(szji1[i]+"和"+szji2[j]);
}
}
}
System.out.println();
System.out.println("-------------------------------");
//请输入星期几的第一个字母来判断一下是星期几，如果第一个字母一样，则继续 判断
//第二个字母。
String day = "二";
if (day=="一"){
System.out.println("星期一");
}else if (day == "二"){
System.out.println("星期二");
}else if (day == "三"){
System.out.println("星期三");
}else if (day == "四"){
System.out.println("星期四");
}else if (day == "五"){
System.out.println("星期五");
}else if (day == "六"){
System.out.println("星期六");
}else if (day == "日"){
System.out.println("星期日");
}
System.out.println("-------------------------------");
//.猴子吃桃问题：猴子第一天摘下若干个桃子，当即吃了一半，还不瘾，又多吃了一个
//第二天早上又将剩下的桃子吃掉一半，又多吃了一个。以后每天早上都吃了前一天剩下
//的一半零一个。到第10天早上想再吃时，见只剩下一个桃子了。求第一天共摘了多少。
System.out.println(fun(1));
}
static int fun (int daiy){
if (daiy == 10){
return 1;
}else{
return (fun(daiy+1)+1)*2;
}
}
}