1、public static void main(String[] args) {
int sum=0;
for(int x=1;x<100;x++){
if(x==2){
System.out.print(x+" ");
sum+=x;
}
for (int i = 2; i <x; i++) {
if (x%i==0) {
break;
}
if(i==x-1){
System.out.print(x+" ");
sum+=x;
}
}
}
System.out.println("\n"+sum);
}
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
1060
2、public static void yangHui(int num){
int[][] a = new int[num][num];
for (int i = 0; i < num; i++){
for (int j = 0; j < num; j++) {
if (j < i) {
a[i][j] = 1;
if (j == 0) {
a[i][j] = 1;
} else {
a[i][j] = a[i - 1][j - 1] + a[i - 1][j];
}
} else {
a[i][j] = 1;
}
}
}
for (int i = num-1; i >= 0; i--) {
for (int k = num - i; k >= 1; k--)
System.out.printf(" ");
for (int j = 0; j <= i; j++) {
System.out.printf("%3d ", a[i][j]);
}
System.out.printf("\n");
}
}
/**
*
*/
public static void main(String[] args) {
System.out.println("请输入一个杨辉三角的行数：");
Scanner input=new Scanner(System.in);
int num=input.nextInt();
yangHui(num);
}
请输入一个杨辉三角的行数：
4
1 3 3 1
1 2 1
1 1
1
3、public static void main(String[] args) {
int[] arr={2,5,9,10,48,95,154,31,59,69};
for (int x = 0; x < arr.length; x++) {
if(arr[x]==2)
arr[x]=0;
for (int i = 2; i <arr[x]; i++) {
if (arr[x]%i==0){
//b=false;
break;
}
if(i==arr[x]-1){
arr[x]=0;
}
}
}
String string="";
for (int i = 0; i < arr.length; i++) {
System.out.print(string);
System.out.println(arr[i]);
string+=" ";
}
}
0
0
9
10
48
95
154
0
0
69
|
