[ACM] CSU 1553 Good subsequence(尺取法）

题目地址：http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1553

给定n的数的序列，求最长连续区间满足区间内的数最大值与最小值的差<=k

(尺取法)

const int maxn=10010;
int num[maxn];
int n,k;
int MIN,MAX;
int main()
{
    while(scanf("%d%d",&n,&k)!=EOF)
    {
        for(int i=1;i<=n;i++)
            scanf("%d",&num[i]);
        int l=1,r=1;
        MAX=MIN=num[1];
        int ans=1;
        while(1)
        {
            if(r>n)
                break;
            while(1)
            {
                MAX=max(MAX,num[r]);
                MIN=min(MIN,num[r]);
                if(MAX-MIN<=k&&r<=n)
                    ans=max(ans,r-l+1);
                if(MAX-MIN<=k)
                    r++;
                else
                    break;
                if(r>n)
                    break;
            }
            if(r>n)
                break;
            bool first=1;
            while(MAX-MIN>k&&l