BZOJ2006【主席树】【优先队列】

对于用RMQ写这道题的菊苣们无限仰慕.

/* I will wait for you */#include<cstdio>#include<cstdlib>#include<cstring>#include<cmath>#include<ctime>#include<algorithm>#include<iostream>#include<fstream>#include<vector>#include<queue>#include<deque>#include<set>#include<map>#include<string>typedef long long LL;typedef unsigned long long ULL;using namespace std;const int maxn=100010;const int maxm=500000010;const int maxs=26;const int INF=1<<29;const int P=1000000007;const double error=1e-9;struct node{int l,r,sum;node *son[2];node(int x,int y) { l=x;r=y;sum=0;son[0]=son[1]=0; }}*su[maxn];struct ans{ int key,id,k; };int n,k,L,R,c[maxn],ml[maxn],mr[maxn];bool operator < (ans a,ans b) { return a.key<b.key; }priority_queue<ans> q;void maintain(node* o){o->sum=0;for(int i=0;i<2;i++) if(o->son[i]) o->sum+=o->son[i]->sum;}node* insert(node* o,int c,int x,int y){node* p=new node(x,y);if(x==y) p->sum=o?o->sum+1:1;else {int mid=x+(y-x)/2;node *ls=o?o->son[0]:0,*rs=o?o->son[1]:0;if(c<=mid) p->son[0]=insert(ls,c,x,mid),p->son[1]=rs;if(c>mid) p->son[1]=insert(rs,c,mid+1,y),p->son[0]=ls;maintain(p);}return p;}int rank(node* x,node* y,int l,int r,int k){if(l==r) return (l+r)/2; int mid=l+(r-l)/2;int xs=x&&x->son[0]?x->son[0]->sum:0;int ys=y&&y->son[0]?y->son[0]->sum:0;int d=(k>ys-xs);node *sx=x?x->son[d]:0,*sy=y?y->son[d]:0;if(k<=ys-xs) return rank(sx,sy,l,mid,k);else return rank(sx,sy,mid+1,r,k-(ys-xs));}int kth(int l,int r,int k){return rank(su[l-1],su[r],-maxm,maxm,k);}int main(){scanf("%d%d%d%d",&n,&k,&L,&R);su[0]=insert(su[0],0,-maxm,maxm);for(int i=1;i<=n;i++) {scanf("%d",&c[i]);c[i]+=c[i-1];su[i]=insert(su[i-1],c[i],-maxm,maxm);ml[i]=max(0,i-R);mr[i]=max(0,i-L);if(i>=L) q.push((ans){c[i]-kth(ml[i],mr[i],1),i,1});}LL fin=0;for(int i=1;i<=k;i++){ans p=q.top();q.pop();fin+=p.key;if(p.k<=mr[p.id]-ml[p.id]) q.push((ans){c[p.id]-kth(ml[p.id],mr[p.id],p.k+1),p.id,p.k+1});}printf("%lld\n",fin);return 0;}