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这题太傻比了
#include #include #include #include #include #include #include #include #include #include using namespace std;#define MAX 150000#define lson (now<<1)#define rson (now<<1|1)struct Node{ double s,ps; double ly;}t[MAX<<4];double a[MAX];int n,m;void Build(int now,int l,int r){ if(l==r) { t[now].s=a[l]; t[now].ps=a[l]*a[l]; return; } int mid=(l+r)>>1; Build(lson,l,mid);Build(rson,mid+1,r); t[now].s=t[lson].s+t[rson].s; t[now].ps=t[lson].ps+t[rson].ps;}void pushdown(int now,int l,int r){ double k=t[now].ly; int mid=(l+r)>>1; t[lson].ly+=k; t[rson].ly+=k; t[lson].ps+=2*t[lson].s*k+(mid-l+1)*k*k; t[rson].ps+=2*t[rson].s*k+(r-mid)*k*k; t[lson].s+=(mid-l+1)*k; t[rson].s+=(r-mid)*k; t[now].ly=0;}void putlazy(int now,int l,int r,double k){ t[now].ly+=k; t[now].ps+=2*t[now].s*k+(r-l+1)*k*k; t[now].s+=(r-l+1)*k;}void Modify(int now,int l,int r,int L,int R,double w){ if(L<=l&&r<=R){putlazy(now,l,r,w);return;} pushdown(now,l,r); int mid=(l+r)>>1; if(L<=mid)Modify(lson,l,mid,L,R,w); if(R>mid)Modify(rson,mid+1,r,L,R,w); t[now].ps=t[lson].ps+t[rson].ps; t[now].s=t[lson].s+t[rson].s;}double Query1(int now,int l,int r,int L,int R){ if(L<=l&&r<=R)return t[now].s; pushdown(now,l,r); double ret=0; int mid=(l+r)>>1; if(L<=mid)ret+=Query1(lson,l,mid,L,R); if(R>mid)ret+=Query1(rson,mid+1,r,L,R); return ret;}double Query2(int now,int l,int r,int L,int R){ if(L<=l&&r<=R)return t[now].ps; pushdown(now,l,r); double ret=0; int mid=(l+r)>>1; if(L<=mid)ret+=Query2(lson,l,mid,L,R); if(R>mid)ret+=Query2(rson,mid+1,r,L,R); return ret;}int main(){ scanf("%d%d",&n,&m); for(int i=1;i<=n;++i)scanf("%lf",&a[i]); Build(1,1,n); int opt,ll,rr; double kk; while(m--) { scanf("%d%d%d",&opt,&ll,&rr); if(opt==1) { scanf("%lf",&kk); Modify(1,1,n,ll,rr,kk); } else if(opt==2) { double ret=Query1(1,1,n,ll,rr); printf("%.4lf\n",ret/(rr-ll+1)); } else { double c1=Query1(1,1,n,ll,rr); double c2=Query2(1,1,n,ll,rr); double c3=c1/(rr-ll+1); double ans=c2-2*c1*c3+(rr-ll+1)*c3*c3; printf("%.4lf\n",ans/(rr-ll+1)); } } return 0;}
转载于:https://www.cnblogs.com/cjyyb/p/8142874.html