手撕第二题只遍历一遍的话感觉可以用单调队列解决
code：
public static int MAX = 100001;
public static int [] maxDeque = new int[MAX];
public static int [] minDeque = new int[MAX];
public static int maxHead,maxTail;
public static int minHead,minTail;
public static int method(int [] nums){
int n = nums.length;
int ans = Integer.MIN_VALUE;
for(int i = 0;i < n;i ++){
while(maxHead < maxTail && nums[maxDeque[maxTail - 1]] < nums[i]){
maxTail--;
}
maxDeque[maxTail++] = i;
while(minHead < minTail && nums[minDeque[minTail - 1]] > nums[i]){
minTail--;
}
minDeque[minTail++] = i;
int max = nums[maxDeque[maxHead]] - nums[minDeque[minHead]];
ans = Math.max(ans,max);
}
return ans;
}
