看到头像进来的举个手
by hpbl @ 2018-08-30 11:36:40
咳咳有句名言是这样的
能用scanf就不用cin能用读入优化就别用scanf
by do_not_use_sort @ 2018-08-30 11:38:27
前缀和qwq
by clockwhite @ 2018-08-30 11:41:39
看到头像进来的举个手
by watermoon @ 2018-08-30 11:42:55
看到头像进的举了个手
by shejian0702 @ 2018-08-30 11:58:50
@[Forever_coding](/space/show?uid=75203) 你这个是埃式筛法吧。。。复杂度最小好像是nlogn，容易被卡，用欧拉筛（线性筛）就不会了。
```cpp
ll euler__ll(ll n){
for(ll i=2;i<=n;i++){
if(!vis[i])p[++cnt]=i;
for(ll j=1;i*p[j]<=n;j++){
p[i*p[j]]=1;
if(i%p[j]==0)break;
}
}
}
```
现场打的，可能会错。。。
by Cesare @ 2018-08-30 12:17:53
看到头像进的举了个手
by 陈独秀先生_ @ 2018-08-30 13:37:01
@[beachfake](/space/show?uid=79153) 陈独秀emmm
by afowww @ 2018-08-30 14:53:17
@[Forever_coding](/space/show?uid=75203) 吸氧气，我也TLE一个点，开氧气就过了
by 醉梦未苏 @ 2018-09-01 22:18:05
@[Forever_coding](/space/show?uid=75203)
加上这个东西之后就A了（没吸氧）：
```
#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
```
by wxy_god @ 2018-09-09 12:37:09