Scanner m = new Scanner(System.in);
int s = m.nextInt();
int[][] str = new int[s][s];
for (int i=0;i<str.length;i++){
for (int j = 0;j<=i;j++){
if(j == 0||j==i){
str[i][j] = 1;
}
else{
str[i][j] = str[i-1][j]+str[i-1][j-1];
}
}
}
//点睛之笔 j<=i ----> 解决了数组的列会越界的问题
for (int i = 0;i < str.length;i++){
for (int j=0;j<=i;j++){
System.out.print(str[i][j]+" ");
}
System.out.println();
}
}
前提是数组有序
static
int BinarySearch(int[] arr, int ele) {
int minIndex = 0;
int maxIndex = arr.length - 1;
int centerIndex = (minIndex + maxIndex) / 2;
while (minIndex <= maxIndex) {
if (ele == arr[centerIndex]) {
return centerIndex;
} else if (ele > arr[centerIndex]) {
minIndex = centerIndex + 1;
} else {
maxIndex = centerIndex - 1;
}
centerIndex = (minIndex + maxIndex) / 2;
}
return -1;
}
package com.sukai;
import java.util.Arrays;
/**
* 解决冒泡排序算法
*/
public class Main {
private static int[] arr = {4,3,2,1,7,5,6};
public static void change(int a,int b){
int temp = 0;
temp = arr[a];
arr[a] = arr[b];
arr[b] = temp;
}
public static void main(String[] args) {
for (int i = 0;i < arr.length;i++){
for (int j = 0;j<arr.length-i-1;j++){
if(arr[j]>arr[j+1]) {
change(j, j + 1);
}
}
}
//使用Arrays.toString()方法
// for (int i = 0;i<arr.length;i++)
// System.out.println(arr[i]);
System.out.println(Arrays.toString(arr));
}
}
public class Main {
public static void FastSort() {
int[] arr = {4, 3, 2, 5, 7, 6, 8};
for (int i = 0; i < arr.length; i++) {
int pos = 0;
for (int j = 1; j < arr.length-i; j++) {
if (arr[pos] < arr[j]) {
pos = j;
}
}
int temp = 0;
temp = arr[pos];
arr[pos] = arr[arr.length-i-1];
arr[arr.length-i-1] = temp;
}
System.out.println(Arrays.toString(arr));
}
public static void main(String[] args)
{
Main.FastSort();
}
}
public void Select_Sort(){
int[] array = new int[]{2,7,6,4,8,5,3};
for(int i = 1;i<array.length;i++){
int pos = array[i];
for(int j=i;j>0;--j){
if(array[j-1]>array[j]){
array[j] = array[j-1];
array[j-1] = pos;
}else{
array[j] = pos;
break;
}
}
}
System.out.print(Arrays.toString(array));
}
public static void quickSort(int[] arr,int low,int high){
if(low>high){
return;
}
int t;
int i = low;
int j = high;
//temp就是基准位
int temp = arr[low];
while (i<j) {
while (temp<=arr[j]&&i<j) {
j--; }
while (temp>=arr[i]&&i<j) {
i++; }
if (i<j) {
t = arr[j]; arr[j] = arr[i]; arr[i] = t;
}
}
arr[low] = arr[i];
arr[i] = temp;
quickSort(arr, low, j-1);
quickSort(arr, j+1, high);