\u5927\u529b\u4e0a\u4e00\u4e2a\u7ebf\u6bb5\u6811\u3002
\n\u5c06\u65b9\u5dee\u5c55\u5f00\u4e3a\u7531\u533a\u95f4\u5e73\u65b9\u7684\u548c\u4e0e\u533a\u95f4\u548c\u4e24\u9879\u6784\u6210\u7684\u591a\u9879\u5f0f\uff0c\u7136\u540e\u7ef4\u62a4\u533a\u95f4\u5e73\u65b9\u7684\u548c\u4e0e\u533a\u95f4\u548c\u3002
\n\u5177\u4f53\u6765\u8bf4\uff0c\u901a\u8fc7\u5c06\u4e8c\u9879\u5f0f\u5c55\u5f00\u53ef\u4ee5\u5f97\u5230\u516c\u5f0f\uff1a
\n$$ \\sum_{i=l}^{r}(a_{i}+k)^2=\\sum_{i=l}^{r}a_{i}^2+\\sum_{i=l}^{r}*k*2+(r-l+1)*k^2 $$
\n\u5957\u7528\u8fd9\u4e2a\u516c\u5f0f\uff0c\u5c31\u53ef\u4ee5\u7528\u4e0e\u7ef4\u62a4\u666e\u901a\u7684\u7ebf\u6bb5\u6811\u76f8\u4f3c\u7684\u65b9\u6cd5\u6765\u7ef4\u62a4\u8fd9\u4e2a\u6570\u636e\u7ed3\u6784\u3002<\/p>\n
#include<iostream>\r\n#include<cstdio>\r\nusing namespace std;\r\n#define LEN (R-L+1)\r\n#define MID ((L+R)>>1)\r\n#define LLEN (MID-L+1)\r\n#define RLEN (R-MID)\r\n#define LS (X<<1)\r\n#define RS (X<<1|1)\r\nstruct data{\r\n\tdouble sm;\r\n\tdouble sm2;\r\n\tdouble lzy;\r\n}tr[270005];\/\/262141\r\ninline void rnw(int X,int Len,double K){\r\n\ttr[X].sm2+=(tr[X].sm*2*K+K*K*Len);\r\n\ttr[X].sm+=(K*Len);\r\n\ttr[X].lzy+=K;\r\n}\r\ninline void pshd(int X,int L,int R){\r\n\trnw(LS,LLEN,tr[X].lzy);rnw(RS,RLEN,tr[X].lzy);\r\n\ttr[X].lzy=0;\r\n}\r\ninline void updt(int X){\r\n\ttr[X].sm2=tr[LS].sm2+tr[RS].sm2;\r\n\ttr[X].sm=tr[LS].sm+tr[RS].sm;\r\n}\r\ninline void add(int X,int L,int R,int A,int B,double K){\r\n\tif(L>=A&&R<=B){\r\n\t\trnw(X,LEN,K);\r\n\t\treturn;\r\n\t}\r\n\tpshd(X,L,R);\r\n\tif(A<=MID){\r\n\t\tadd(LS,L,MID,A,B,K);\r\n\t}\r\n\tif(B>MID){\r\n\t\tadd(RS,MID+1,R,A,B,K);\r\n\t}\r\n\tupdt(X);\r\n}\r\ninline double qrySm(int X,int L,int R,int A,int B){\r\n\tif(L>=A&&R<=B){\r\n\t\treturn tr[X].sm;\r\n\t}\r\n\tpshd(X,L,R);\r\n\tdouble rt=0;\r\n\tif(A<=MID){\r\n\t\trt+=qrySm(LS,L,MID,A,B);\r\n\t}\r\n\tif(B>MID){\r\n\t\trt+=qrySm(RS,MID+1,R,A,B);\r\n\t}\r\n\treturn rt;\r\n}\r\ninline double qrySm2(int X,int L,int R,int A,int B){\r\n\tif(L>=A&&R<=B){\r\n\t\treturn tr[X].sm2;\r\n\t}\r\n\tpshd(X,L,R);\r\n\tdouble rt=0;\r\n\tif(A<=MID){\r\n\t\trt+=qrySm2(LS,L,MID,A,B);\r\n\t}\r\n\tif(B>MID){\r\n\t\trt+=qrySm2(RS,MID+1,R,A,B);\r\n\t}\r\n\treturn rt;\r\n}\r\nint n,m;\r\ndouble a[100005];\r\ninline void build(int X,int L,int R){\r\n\tif(L==R){\r\n\t\ttr[X].sm=a[L];\r\n\t\ttr[X].sm2=a[L]*a[R];\r\n\t\treturn;\r\n\t}\r\n\tbuild(LS,L,MID);build(RS,MID+1,R);\r\n\tupdt(X);\r\n}\r\nvoid init(){\r\n\tscanf(\"%d%d\",&n,&m);\r\n\tdouble x;\r\n\tfor(int i=1;i<=n;++i){\r\n\t\tscanf(\"%lf\",a+i);\r\n\t}\r\n\tbuild(1,1,n);\r\n\tint op,l,r;\r\n\twhile(m--){\r\n\t\tscanf(\"%d%d%d\",&op,&l,&r);\r\n\t\tif(op==1){\r\n\t\t\tscanf(\"%lf\",&x);\r\n\t\t\tadd(1,1,n,l,r,x);\r\n\t\t}else if(op==2){\r\n\t\t\tprintf(\"%.4lf\\n\",qrySm(1,1,n,l,r)\/(r-l+1));\r\n\t\t}else{\r\n\t\t\tx=qrySm(1,1,n,l,r);\r\n\t\t\tprintf(\"%.4lf\\n\",(qrySm2(1,1,n,l,r)-x*x\/(r-l+1))\/(r-l+1));\r\n\t\t}\r\n\t}\r\n}\r\nint main(){\r\n\tinit();\r\n\treturn 0;\r\n}<\/code><\/pre>\n <\/p>\n","protected":false},"excerpt":{"rendered":"
\u5927\u529b\u4e0a\u4e00\u4e2a\u7ebf\u6bb5\u6811\u3002 \u5c06\u65b9\u5dee\u5c55\u5f00\u4e3a\u7531\u533a\u95f4\u5e73\u65b9\u7684\u548c\u4e0e\u533a\u95f4\u548c\u4e24\u9879\u6784\u6210\u7684\u591a\u9879\u5f0f\uff0c\u7136\u540e\u7ef4\u62a4\u533a\u95f4\u5e73\u65b9\u7684\u548c\u4e0e\u533a\u95f4\u548c\u3002 \u5177\u4f53\u6765 … <\/p>\n