hdu3308 线段树——区间合并

更新一个点；

求某个区间的最长连续上升序列；

链接：http://acm.hdu.edu.cn/showproblem.php?pid=3308

 #include <cstdio>
 #include <algorithm>
 using namespace std;
 #define maxn 100009
 #define mid int m=(l+r)>>1
 int num[maxn], lsum[maxn<<], rsum[maxn<<], msum[maxn<<], n, m, p, v, a, b;
 void pushup(int o, int l, int r)
 {
     mid;
     if (num[m] < num[m+])
     {
         lsum[o] = (lsum[o<<] == m+-l) ? (m+-l+lsum[o<<|]) : lsum[o<<];
         rsum[o] = (rsum[o<<|] == r-m) ? (r-m+rsum[o<<]) : rsum[o<<|];
         msum[o] = max(max(msum[o<<], msum[o<<|]), lsum[o<<|] + rsum[o<<]);
     }
     else lsum[o] = lsum[o<<], rsum[o] = rsum[o<<|], msum[o] = max(msum[o<<], msum[o<<|]);
 }
 void build(int o, int l, int r)
 {
     if (l == r) {lsum[o]= rsum[o] = msum[o] = ; return;}
     mid; build(o<<, l, m), build(o<<|, m+, r), pushup(o, l, r);
 }
 void update(int o, int l, int r)
 {
     if (l == r) {num[p] = v; return;}
     mid; if (p <= m) update(o<<, l, m); else update(o<<|, m+, r); pushup(o, l, r);
 }
 int query(int o, int l, int r)
 {
     if (a <= l && b >= r) return msum[o];
     mid; int ret = ;
     if (a <= m) ret = max(ret, query(o<<, l, m)); if (b > m) ret = max(ret, query(o<<|, m+, r));
     if (num[m] < num[m+]) ret = max(ret, min(m-a+, rsum[o<<])+min(b-m, lsum[o<<|])); return ret;
 }
 int main(void)
 {
     int t, n, m; char ch[]; scanf("%d", &t);
     while (t--)
     {
         scanf("%d%d", &n, &m); for (int i = ; i <= n; scanf("%d", num+i++)); build(, , n);
         while (m--)
         {
             scanf("%s%d%d", ch, &a, &b); a++, b++;
             if (ch[] == 'Q') printf("%d\n", query(, , n)); else p = a, v = b-, update(, , n);
         }
     }
     return ;
 }

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