給定一個含有n個元素的整型數組a,求a中的最大值和最小值。用遞歸實現。
public class MaxAnsMinInArr {
public static void main(String[] args) {
// TODO 自動生成的方法存根
int[] arr = new int[2];
int[] a = {1,8,1,84,4,9,102,74,52,3,30,55,84};
int l = 0,r=a.length-1;
maxAndMinArr(a, l, r, arr);
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i]);
}
}
private static void maxAndMinArr(int[] a, int l, int r, int[] ret){
if (l == r) {
ret[0] = a[l];
ret[1] = a[l];
return;
}
if (l + 1 ==r) {
if (a[l] >= a[r]) {
ret[0] = a[r];
ret[1] = a[l];
}
else {
ret[0] = a[l];
ret[1] = a[r];
}
return;
}
int m = (l + r) / 2;
int[] larr = new int[2];
maxAndMinArr(a, l, m, larr);
int[] rarr = new int[2];
maxAndMinArr(a, m+1, r, rarr);
ret[0] = min(larr[0],rarr[0]);
ret[1] = max(larr[1],rarr[1]);
}
public static int min(int lmin,int rmin){
return lmin < rmin ? lmin : rmin;
}
public static int max(int lmax,int rmax){
return lmax > rmax ? lmax : rmax;
}
}