文档介绍：JAVA基础编程练****题【程序1】/*机选双色球:{"01","02","03","04","05","06","07","08","09","10",~33}{false,true,false,false....}*/.*;classDemo07{ publicstaticvoidmain(String[]args) { String[]redBalls=getBalls(); ((redBalls)); } /*定义方法返回值类型:String[] 参数:无 */ publicstaticString[]getBalls(){ String[]pool={ "01","02","03","04","05","06","07","08","09","10", "11","12","13","14","15","16","17","18","19","20", "21","22","23","24","25","26","27","28","29","30", "31","32","33"}; boolean[]flags=newboolean[33]; String[]balls=newString[7]; Randomr=newRandom(); inti=0; for(;;){ intindex=(); if(!flags[index]){//flags==false balls[i]=pool[index]; i++; flags[index]=true; } if(i==6){ break; } } intblueIndex=(16); balls[6]=pool[blueIndex]; (balls[6]); //对数组的排序 (balls,0,5); returnballs; }}【程序2】题目:古典问题:有一对兔子,从出生后第3个月起每个月都生一对兔子,小兔子长到第三个月后每个月又生一对兔子,假如兔子都不死,问每个月的兔子对数为多少?程序分析:兔子的规律为数列1,1,2,3,5,8,13,21....lassProg1{ publicstaticvoidmain(String[]args){ intn=10; ("第"+n+"个月兔子总数为"+fun(n)); } privatestaticintfun(intn){ if(n==1||n==2) return1; else returnfun(n-1)+fun(n-2); }}【程序3】题目:判断101-200之间有多少个素数,并输出所有素数。程序分析:判断素数的方法:用一个数分别去除2到sqrt(这个数),如果能被整除,则表明此数不是素数,反之是素数。lassProg2{ publicstaticvoidmain(String[]args){ intm=1; intn=1000; intcount=0; //统计素数个数 for(inti=m;i<n;i++){ if(isPrime(i)){ count++; (i+""); if(count%10==0){ (); } } } (); ("在"+m+"和"+n+"之间共有"+count+"个素数"); } //判断素数 privatestaticbooleanisPrime(intn){ booleanflag=true; if(n==1) flag=false; else{ for(inti=2;i<=(n);i++){ if((n%i)==0||n==1){ flag=false; break; } else flag=true; } } returnflag; }}【程序4】题目:打印出所有的"水仙花数",所谓"水仙花数"是指一个三位数,其各位数字立方和等于该数本身。例如:153是一个"水仙花数",因为153=1的三次方+5的三次方+3的三次方。程序分析:利用for循环控制100-999个数,每个数分解出个位,十位,百位。lassProg3{ publicstaticvoidmain(String[]args){ for(inti=100;i<1000;i++){ if(isLotus(i)) (i+""); } (); } //判断水