题意 给你一个数组 有更新值和查询两种操作 对于每次查询 输出相应区间的最长连续递增子序列的长度
基础的线段树区间合并 线段树维护三个值 相应区间的LCIS长度(lcis) 相应区间以左端点为起点的LCIS长度(lle) 相应区间以右端点为终点的LCIS长度(lri) 然后用val存储数组相应位置的值 当val[mid + 1] > val[mid] 的时候就要进行区间合并操作了
#include <cstdio> #include <algorithm> #define lc lp, s, mid #define rc rp, mid+1, e #define lp p<<1 #define rp p<<1|1 #define mid ((s+e)>>1) using namespace std; const int N = 100005, M = N * 4; int lcis[M], lle[M], lri[M], val[N]; void pushup(int p, int s, int e) { lcis[p] = max(lcis[lp], lcis[rp]); lle[p] = lle[lp], lri[p] = lri[rp]; if(val[mid + 1] > val[mid]) //合并条件 { lcis[p] = max(lcis[p], lri[lp] + lle[rp]); if(lle[lp] == mid + 1 - s) lle[p] += lle[rp]; if(lri[rp] == e - mid) lri[p] += lri[lp]; } } void build(int p, int s, int e) { if(s == e) { lcis[p] = lle[p] = lri[p] = 1; scanf("%d", &val[s]); return; } build(lc); build(rc); pushup(p, s, e); } void update(int p, int s, int e, int x, int v) { if(s == e) { val[s] = v; return; } if(x <= mid) update(lc, x, v); else if(x > mid) update(rc, x, v); pushup(p, s, e); } int query(int p, int s, int e, int l, int r) { if(l <= s && e <= r) return lcis[p]; int ret = 0; if(val[mid + 1] > val[mid]) ret = min(r, mid + lle[rp]) - max(l, mid + 1 - lri[lp]) + 1; if(l <= mid) ret = max(ret, query(lc, l, r)); if(r > mid) ret = max(ret, query(rc, l, r)); return ret; } int main() { int T, n, m, a, b; char op[5]; scanf("%d", &T); while(T--) { scanf("%d%d", &n, &m); build(1, 0, n - 1); while(m--) { scanf("%s%d%d", op, &a, &b); if(op[0] == 'Q') printf("%d\n", query(1, 0, n - 1, a, b)); else update(1, 0, n - 1, a, b); } } return 0; }
LCIS
Problem Description
Given n integers.
You have two operations:
U A B: replace the Ath number by B. (index counting from 0)
Q A B: output the length of the longest consecutive increasing subsequence (LCIS) in [a, b].
You have two operations:
U A B: replace the Ath number by B. (index counting from 0)
Q A B: output the length of the longest consecutive increasing subsequence (LCIS) in [a, b].
Input
T in the first line, indicating the case number.
Each case starts with two integers n , m(0<n,m<=105).
The next line has n integers(0<=val<=105).
The next m lines each has an operation:
U A B(0<=A,n , 0<=B=105)
OR
Q A B(0<=A<=B< n).
Each case starts with two integers n , m(0<n,m<=105).
The next line has n integers(0<=val<=105).
The next m lines each has an operation:
U A B(0<=A,n , 0<=B=105)
OR
Q A B(0<=A<=B< n).
Output
For each Q, output the answer.
Sample Input
1 10 10 7 7 3 3 5 9 9 8 1 8 Q 6 6 U 3 4 Q 0 1 Q 0 5 Q 4 7 Q 3 5 Q 0 2 Q 4 6 U 6 10 Q 0 9
Sample Output
1 1 4 2 3 1 2 5