每个元素和后一个元素比较看是不是希望的次序,如果不是的话互换就好
public void wiggle_sort(int[] arr) {
int n = arr.length;
if(n <= 1) return;
boolean inc = true;
int prev = arr[0];
for(int i=1; i<n; i++) {
if((inc && prev <= arr[i]) || (!inc && prev >= arr[i])) {
arr[i-1] = prev;
prev = arr[i];
} else {
arr[i-1] = arr[i];
}
inc = !inc;
}
}