POJ 3017 Monotone Queue

Can only say that the code is beautiful as a picture. (Of course I mean the inner logic is not my Code style, captain see to understand ha, ah haha haha haha)

Normal thinking, F[i]=f[j]+max (A[j+1],a[j+2]....a[i]), enumeration J, obviously hard to time out, so need to have a monotone queue to always get the maximum value as soon as possible and need some pruning;

The pruning condition has two, one is and cannot exceed M, one is obviously f[i] is a non-strict increment sequence, according to these two conditions pruning;

Then set up a monotone queue, each time I insert a new I will be preceded by the first and less than equal to the conditions of M, and then for J<i, if A[j]<a[i] can throw J, then obviously the newly added elements will become the smallest of the monotone queue, the monotone ranks as descending sequence.

And then just look at the code.

1#include <cstdio>2#include <cstring>3#include <Set>4#include <iostream>5#include <map>6#include <math.h>7#include <algorithm>8#include <vector>9 using namespacestd;Ten  OnetypedefLong Longll; A  - Const intn=100005; - Const Long Longinf=1000000000LL; the intN; - ll M; - ll A[n],f[n]; - ll Solve () { + inti,j,k=0, fg=0, l=0, r=0; - intQ[n]; +ll sum=0; A  for(i=1; i<=n;i++){ atsum+=A[i]; -      while(sum>m) sum-=a[++K]; -     if(k>=i) { -fg=1; -          Break; -     } in     while(L<=r&&a[q[r]]<=a[i]) r--;//the equals sign is the detail . -q[++r]=i; to     while(l<=r&&q[l]<=k) l++; + ll tmp; -    intkk=K; thef[i]=INF; *         //cout<<l<< "" <<r<< "" <<kk<<endl; $          for(j=l; j<=r; j + +)//the queue-optimized DP process ensures that the elements in the monotone queue are decrementedPanax Notoginseng         { -tmp=f[kk]+A[q[j]]; the           //cout<<tmp<< "<<f[i]<<" "<<i<<" "<<kk<<endl; +             if(Tmp<f[i]) f[i]=tmp; AKK=Q[J];//KK indicates that the current maximum value exists in the range of [Kk+1,i] the         } + //f[i]=tmp; - //cout<<f[i]<< "" <<i<<endl; $ } $ if(FG) -     return-1; - Else the     returnF[n]; - }Wuyi intMain () the { -Freopen ("In.txt","R", stdin); WuCin>>n>>m; -    inti; About     for(i=1; i<=n;i++) $scanf"%lld",&a[i]); -Cout<<solve () <<Endl; -     return 0; -}

POJ 3017 Monotone Queue