//直线查找法
int[] array= {10,20,30,40,50};
System.out.println("请输入要查找的数：");
Scanner scanner = new Scanner(System.in);
int number = scanner.nextInt();
int index = -1;
for(int i=0;i<array.length;i++) {
if(array[i]==number) {
index=i+1;
break;
}
}
if(index!=-1) {
System.out.println("找到，在数组中的第"+index+"位置");
}else {
System.out.println("不存在");
}
System.out.println("请输入要查找的数：");
Scanner scanner = new Scanner(System.in);
int number = scanner.nextInt();
int index= -1;
int start=0; //起始下标
int end=array.length-1; //终止下标
int middle;
while(start<=end) {
//找到中间下标所对应的元素值
middle=(start+end)/2;
if(number==array[middle]) {
index=middle+1;
break;
}
/*
* 假如要查找的数大于中间比较的那个数，
* 去掉左边的的数
*/
if(number>array[middle]) {
start=middle+1;
}
//保留左边的，去掉右边的
if(number<array[middle]) {
end=middle-1;
}
}
if(index == -1){
System.out.println("not find");
}else {
System.out.println("find"+index);
}
int[] array= {10,20,30,40,50};
System.out.println("请输入要查找的数：");
Scanner scanner = new Scanner(System.in);
int number = scanner.nextInt();
int index = -1;
for(int i=0;i<array.length;i++) {
if(array[i]==number) {
index=i+1;
break;
}
}
if(index!=-1) {
System.out.println("找到，在数组中的第"+index+"位置");
}else {
System.out.println("不存在");
}
//二分查找法
int[] array= {10,20,30,40,50,70,71,80,89};System.out.println("请输入要查找的数：");
Scanner scanner = new Scanner(System.in);
int number = scanner.nextInt();
int index= -1;
int start=0; //起始下标
int end=array.length-1; //终止下标
int middle;
while(start<=end) {
//找到中间下标所对应的元素值
middle=(start+end)/2;
if(number==array[middle]) {
index=middle+1;
break;
}
/*
* 假如要查找的数大于中间比较的那个数，
* 去掉左边的的数
*/
if(number>array[middle]) {
start=middle+1;
}
//保留左边的，去掉右边的
if(number<array[middle]) {
end=middle-1;
}
}
if(index == -1){
System.out.println("not find");
}else {
System.out.println("find"+index);
}