loj2512 [BJOI2018]链上二次求和
作者:互联网
分析
代码
#include<iostream> #include<cstdio> #include<cstring> #include<string> #include<algorithm> #include<cctype> #include<cmath> #include<cstdlib> #include<queue> #include<ctime> #include<vector> #include<set> #include<map> #include<stack> using namespace std; #define int long long const int mod = 1e9+7; const int t = 5e8+4; int n,m,p[200100],pp[200100],d[20000100],Ans,f1[200100],f2[200100]; int cola[20000100],colb[20000100],colc[20000100]; inline void build(int le,int ri,int wh){ if(le==ri){ d[wh]=pp[le]*2%mod; return; } int mid=(le+ri)>>1; build(le,mid,wh<<1); build(mid+1,ri,wh<<1|1); d[wh]=(d[wh<<1]+d[wh<<1|1])%mod; } inline int S(int le,int ri,int a,int b,int c){ int res=c*(ri-le+1)%mod+b*((f1[ri]-(le?f1[le-1]:0)+mod)%mod)%mod +a*((f2[ri]-(le?f2[le-1]:0)+mod)%mod)%mod; return res%mod; } inline void pd(int wh,int le,int mid,int ri){ int a=cola[wh],b=colb[wh],c=colc[wh]; if(!a&&!b&&!c)return; cola[wh<<1]+=a,colb[wh<<1]+=b,colc[wh<<1]+=c; cola[wh<<1]%=mod,colb[wh<<1]%=mod,colc[wh<<1]%=mod; d[wh<<1]+=S(le,mid,a,b,c); d[wh<<1]%=mod; cola[wh<<1|1]+=a,colb[wh<<1|1]+=b,colc[wh<<1|1]+=c; cola[wh<<1|1]%=mod,colb[wh<<1|1]%=mod,colc[wh<<1|1]%=mod; d[wh<<1|1]+=S(mid+1,ri,a,b,c); d[wh<<1|1]%=mod; cola[wh]=colb[wh]=colc[wh]=0; } inline void update(int le,int ri,int wh,int x,int y,int a,int b,int c){ if(le>=x&&ri<=y){ cola[wh]+=a,colb[wh]+=b,colc[wh]+=c; cola[wh]%=mod,colb[wh]%=mod,colc[wh]%=mod; d[wh]+=S(le,ri,a,b,c); d[wh]%=mod; return; } int mid=(le+ri)>>1; pd(wh,le,mid,ri); if(mid>=x)update(le,mid,wh<<1,x,y,a,b,c); if(mid<y)update(mid+1,ri,wh<<1|1,x,y,a,b,c); d[wh]=(d[wh<<1]+d[wh<<1|1])%mod; } inline int q(int le,int ri,int wh,int x,int y){ if(le>=x&&ri<=y)return d[wh]; int mid=(le+ri)>>1,ans=0; pd(wh,le,mid,ri); if(mid>=x)ans=(ans+q(le,mid,wh<<1,x,y))%mod; if(mid<y)ans=(ans+q(mid+1,ri,wh<<1|1,x,y))%mod; d[wh]=(d[wh<<1]+d[wh<<1|1])%mod; return ans; } signed main(){ int i,j,k; scanf("%lld%lld",&n,&m); for(i=1;i<=n;i++)scanf("%lld",&p[i]),p[i]=(p[i]+p[i-1])%mod; for(i=1;i<=n;i++)pp[i]=(pp[i-1]+p[i])%mod; for(i=1;i<=n;i++)f1[i]=(f1[i-1]+i)%mod,f2[i]=(f2[i-1]+i*i)%mod; build(0,n,1); for(i=1;i<=m;i++){ scanf("%lld",&k); int le,ri,len,D; if(k==1){ scanf("%lld%lld%lld",&le,&ri,&D); if(le>ri)swap(le,ri); len=ri-le+1; int a=D,b=(3-2*le%mod+mod)%mod*D%mod; int c=(le*le%mod-3*le%mod+2+mod)%mod*D%mod; update(0,n,1,le,ri,a,b,c); if(ri==n)continue; a=0,b=2*len*D%mod,c=(len*(len+1-2*ri)%mod+mod)%mod*D%mod; update(0,n,1,ri+1,n,a,b,c); }else { scanf("%lld%lld",&le,&ri); len=ri-le+1; Ans=len*q(0,n,1,n,n)%mod; Ans=(Ans-q(0,n,1,le-1,ri-1)+mod)%mod; Ans=(Ans-q(0,n,1,n-ri,n-le)+mod)%mod; printf("%lld\n",Ans*t%mod); } } return 0; }
标签:BJOI2018,le,int,loj2512,mid,链上,include,ri,mod 来源: https://www.cnblogs.com/yzxverygood/p/10382268.html