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 }