Hdu 3308 LCIs (segment tree)

pid=3308 "target=" _blank "style=" "> topic Links: hdu 3308 LCIs

Topic: Given a sequence, two operations:

• Q L R: longest continuous increment sequence length in l,r between Sany
• U p x: Change the number on position p to X

Problem-solving idea: The interval merging on the line tree, which is to infer whether the increment is satisfied when the left and right sub-tree merges.

#include <cstdio>#include <cstring>#include <algorithm>using namespace STD;Const intMAXN =1e5+5;intN, M, A[MAXN];#Define Lson (x) ((x) <<1)#Define Rson (x) (((x) <<1) |intLC[MAXN <<2], RC[MAXN <<2];intL[MAXN <<2], R[MAXN <<2], S[MAXN <<2];voidPushup (intu) {intMID = (Lc[u] + rc[u])/2; S[u] = max (max (S[lson (U), S[rson (U)]), (A[mid] < a[mid+1] ? R[lson (U)] + L[rson (u)]:0)); L[u] = L[lson (u)] + (L[lson (u)] = = Rc[lson (u)]-Lc[lson (u)] +1&& A[mid] < A[mid +1] ?
L[rson (U)]: 0); R[u] = R[rson (u)] + (R[rson (u)] = = Rc[rson (u)]-Lc[rson (u)] + 1 && A[mid] < A[mid + 1]?
R[lson (U)]:0);}voidBuild (intUintLintR) {Lc[u] = l; Rc[u] = r;if(L = = r) {L[u] = R[u] = S[u] =1;return; }intMid = (L + r)/2; Build (Lson (U), L, mid); Build (Rson (U), Mid +1, R); Pushup (u);}voidModify (intUintXintV) {if(Lc[u] = = x && Rc[u] = = x) {A[x] = V;return; }intMID = (Lc[u] + rc[u])/2;if(x <= mid) Modify (Lson (U), X, V);ElseModify (Rson (U), X, V); Pushup (u);}intQuery (intUintLintR) {if(l <= Lc[u] && Rc[u] <= R)returnS[u];intMID = (Lc[u] + rc[u])/2, ret;if(R <= mid) ret = query (Lson (U), L, R);Else if(L > Mid) ret = query (Rson (U), L, R);Else{intll = query (Lson (U), L, R);intrr = Query (Rson (U), L, R);intA = min (R[lson (u)], mid-l +1);intB = min (L[rson (u)], r-mid); RET = max (LL, RR), A[mid] < A[mid +1] ?
A + B:0); }returnRET;}intMain () {intCAsscanf("%d", &cas); while(cas--) {scanf("%d%d", &n, &m); for(inti =0; i < N; i++)scanf("%d", &a[i]); Build1,0, N-1);intL, R;Charop[5]; while(m--) {scanf("%s%d%d", OP, &l, &r);if(op[0] ==' U ') Modify (1, l, R);Else printf("%d\n", Query (1, L, R)); } }return 0;}

Hdu 3308 LCIs (segment tree)