hdu3308--LCIS 最大连续递增序列长度

这个是动态的，所以要用线段树维护。代码里有注释因为ls敲成lsum，rs敲成rsum查错查了好久。。

  1 #include <set>
  2 #include <map>
  3 #include <cmath>
  4 #include <ctime>
  5 #include <queue>
  6 #include <stack>
  7 #include <cctype>
  8 #include <cstdio>
  9 #include <string>
 10 #include <vector>
 11 #include <cstdlib>
 12 #include <cstring>
 13 #include <iostream>
 14 #include <algorithm>
 15 using namespace std;
 16 typedef unsigned long long ull;
 17 typedef long long ll;
 18 const int inf = 0x3f3f3f3f;
 19 const double eps = 1e-8;
 20 template <class T>
 21 inline bool scan_d(T &ret)
 22 {
 23     char c;
 24     int sgn;
 25     if(c=getchar(),c==EOF) return 0;
 26     while(c!=‘-‘&&(c<‘0‘||c>‘9‘))
 27         c=getchar();
 28     sgn=(c==‘-‘)?-1:1;
 29     ret=(c==‘-‘)?0:(c-‘0‘);
 30     while(c=getchar(),c>=‘0‘&&c<=‘9‘)
 31         ret=ret*10+(c-‘0‘);
 32     ret*=sgn;
 33     return 1;
 34 }
 35
 36 const int maxn = 1e5+10;
 37 int ls[maxn<<2],rs[maxn<<2];       //ls为区间左值，rs为区间右值  比较时要用到。
 38 int lsum[maxn<<2],rsum[maxn<<2],sum[maxn<<2];  //lsum为区间左上升长度，rsum为区间右上升长度，sum为区间最大上升长度。
 39
 40 void push_up(int l,int r,int pos)
 41 {
 42     ls[pos] = ls[pos<<1];
 43     rs[pos] = rs[pos<<1|1];
 44     lsum[pos] = lsum[pos<<1];
 45     rsum[pos] = rsum[pos<<1|1];
 46     sum[pos] = max(sum[pos<<1],sum[pos<<1|1]);
 47     int mid = (l + r) >> 1;
 48     if (ls[pos<<1|1] > rs[pos<<1])
 49     {
 50         sum[pos] = max(sum[pos],rsum[pos<<1] + lsum[pos<<1|1]);
 51         if (lsum[pos<<1] == mid - l + 1)               //左区间左上升长度已满
 52             lsum[pos] += lsum[pos<<1|1];
 53         if (rsum[pos<<1|1] == r - mid)                 //同理，
 54             rsum[pos] += rsum[pos<<1];
 55     }
 56 }
 57
 58 void build (int l,int r,int pos)
 59 {
 60     if (l == r)
 61     {
 62         int tmp;
 63         scanf ("%d",&tmp);
 64         ls[pos] = tmp;
 65         rs[pos] = tmp;
 66         lsum[pos] = rsum[pos] = sum[pos] = 1;
 67         return;
 68     }
 69     int mid =(l + r) >> 1;
 70     build(l,mid,pos<<1);
 71     build(mid+1,r,pos<<1|1);
 72     push_up(l,r,pos);
 73 }
 74
 75 void update(int l,int r,int pos,int x,int val)
 76 {
 77     if (l == r)
 78     {
 79         ls[pos] = rs[pos] = val;
 80         return;
 81     }
 82     int mid = (l + r) >> 1;
 83     if (x <= mid)
 84         update(l,mid,pos<<1,x,val);
 85     else
 86         update(mid+1,r,pos<<1|1,x,val);
 87     push_up(l,r,pos);
 88 }
 89
 90
 91 int query(int l,int r,int pos,int ua,int ub)
 92 {
 93     if (ua <= l && ub >= r)
 94     {
 95         return sum[pos];
 96     }
 97     int mid = (l + r) >> 1;
 98     int ans1 = 0,ans2 = 0,ans3 = 0;
 99     if (ua <= mid)
100         ans1 = query(l,mid,pos<<1,ua,ub);
101     if (ub > mid)
102         ans2 = query(mid+1,r,pos<<1|1,ua,ub);
103     if (ls[pos<<1|1] > rs[pos<<1])
104         ans3 = min(lsum[pos<<1|1],ub-mid) + min(rsum[pos<<1],mid-ua+1);
105     return max(ans1,max(ans2,ans3));
106 }
107
108
109 int main(void)
110 {
111     #ifndef ONLINE_JUDGE
112     freopen("in.txt","r",stdin);
113     #endif
114     int t;
115     cin>>t;
116     while (t--)
117     {
118         int n,q;
119         scanf ("%d%d",&n,&q);
120         build(1,n,1);
121         char op[10];
122         int x,y;
123         for (int i = 0; i < q; i++)
124         {
125             scanf ("%s%d%d",op,&x,&y);
126             if (op[0] == ‘Q‘)
127                 printf("%d\n",query(1,n,1,x+1,y+1));
128             if (op[0] == ‘U‘)
129                 update(1,n,1,x+1,y);
130         }
131     }
132     return 0;
133 }