[hdu1506] monotone queue (stack)

Test instructions: http://acm.hdu.edu.cn/showproblem.php?pid=1506 look at the picture at a glance. Two-direction monotonic queue maintenance.

1#include <iostream>2#include <cstdio>3#include <algorithm>4#include <cstdlib>5#include <cstring>6#include <map>7#include <queue>8#include <deque>9#include <cmath>Ten#include <vector> One#include <ctime> A#include <cctype> -#include <Set> -  the using namespacestd; -  - #defineMem0 (a) memset (a, 0, sizeof (a)) - #defineLson L, M, RT << 1 + #defineRson m + 1, R, RT << 1 | 1 - #definedefine_m int m = (L + r) >> 1 + #defineRep (A, b) for (int a = 0; a < b; a++) A #defineLowbit (x) ((x) & (-(x))) at #defineCONSTRUCTINT4 (name, a, B, C, D) name (int a = 0, int b = 0, int c = 0, int d = 0): A (a), B (b), C (c), D (d) {} - #defineCONSTRUCTINT3 (name, a, B, c) name (int a = 0, int b = 0, int c = 0): A (a), B (b), C (c) {} - #defineConstructInt2 (name, a, b) name (int a = 0, int b = 0): A (a), B (b) {} -  -typedefDoubledb; -typedefLong LongLL; intypedef pair<int,int>PII; -typedef multiset<int>MSI; totypedef multiset<int>:: iterator msii; +typedefSet<int>si; -typedefSet<int>:: iterator sii; the  * Const intdx[8] = {1,0, -1,0,1,1, -1, -1}; $ Const intdy[8] = {0, -1,0,1, -1,1,1, -1};Panax Notoginseng Const intMAXN = 1e6 +7; - Const intMAXM = 1e5 +7; the Const intMD = 1e9 +7; + Const intINF = 1e9 +7; A  thetemplate<classT>structmonotonequeue{ +Deque<t>Q; -Monotonequeue<t>() {q.clear ();} $     voidClear () {q.clear ();} $     BOOLEmpty () {returnq.empty ();} -     voidAdd_back (T x) { while(! Q.empty () &&! (Q.back () <x)) Q.pop_back (); Q.push_back (x); } -     voidPop_front () {Q.pop_front ();} theT Back2 () {return* (Q.end ()-2); } -T Front () {returnQ.front ();}Wuyi }; the  - structPair1 { Wu     intVal, pos; -     BOOL operator< (ConstPair1 &a)Const { About         returnVal <A.val; $     } - ConstructInt2 (Pair1, Val, pos); - }; -  AMonotonequeue<pair1>UQ; +  the inta[100010], l[100010]; -  $ intMain () { the     //freopen ("In.txt", "R", stdin); the     intN; the      while(Cin >>N, N) { the uq.clear (); -Uq.add_back (Pair1 (-1, -1)); in          for(inti =0; I < n; i++) { thescanf"%d", A +i); the Uq.add_back (Pair1 (a[i], i)); AboutL[i] = Uq.back2 (). Pos +1; the         } the uq.clear (); theUq.add_back (Pair1 (-1, N)); +LL ans =0; -          for(inti = n-1; I >=0; i--) { the Uq.add_back (Pair1 (a[i], i));Bayians = max (ans, (LL) a[i] * (Uq.back2 (). POS-l[i])); the         } thecout << ans <<Endl; -     } -     return 0; the}

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[hdu1506] monotone queue (stack)