关于优化(c++)
下面是我给的一个终极优化代码(c++)：
点我（GCC板块）
点我（G++板块）
这个优化代码长度为94行，分为两部分：GCC与G++；
其中GCC与G++的两部分除了GCC与G++的区别外完全重合；
下面给这其中一段打上注释：
#pragma GCC optimize(1)//o1优化
#pragma GCC optimize(2)//o2优化
#pragma GCC optimize(3)//03优化
#pragma GCC optimize("Ofast")//ofast优化
#pragma GCC optimize("inline")//inline中和
#pragma GCC optimize("-fgcse")//fgcse优化
#pragma GCC optimize("-fgcse-lm")//-fgcse-lm
#pragma GCC optimize("-fipa-sra")//除换
#pragma GCC optimize("-ftree-pre")//快速tree
#pragma GCC optimize("-ftree-vrp")//去重tree
#pragma GCC optimize("-fpeephole2")//flatco2优化
#pragma GCC optimize("-ffast-math")//数论优化
#pragma GCC optimize("-fsched-spec")//富硒优化
#pragma GCC optimize("unroll-loops")//图论plus优化
#pragma GCC optimize("-falign-jumps")//极优化
#pragma GCC optimize("-falign-loops")//图论重+排除
#pragma GCC optimize("-falign-labels")//lamb优化
#pragma GCC optimize("-fdevirtualize")//fugechar优化
#pragma GCC optimize("-fcaller-saves")//负优化排除
#pragma GCC optimize("-fcrossjumping")//极优化p+
#pragma GCC optimize("-fthread-jumps")//多重极优化
#pragma GCC optimize("-funroll-loops")//天花板算法优化
#pragma GCC optimize("-fwhole-program")//弗洛伊德优化
#pragma GCC optimize("-freorder-blocks")//半刻优化
#pragma GCC optimize("-fschedule-insns")//fschedule-insns优化
#pragma GCC optimize("inline-functions")//inline-functions优化
#pragma GCC optimize("-ftree-tail-merge")//-ftree-tail-merge优化
#pragma GCC optimize("-fschedule-insns2")//-fschedule-insns2优化
#pragma GCC optimize("-fstrict-aliasing")//-fstrict-aliasing优化
1.其中有些有特殊含义，单独存在，like：O1\O2\O3\OFAST等等，但是有有些事辅佐优化，像（我打圈圈的）：查看图片请点我
2、注释是通用的，也只是把后面("")中的内容写一遍，给大家一个实际的优化例子，用一道题来证明（我打圈的地方是耗时）：
不开优化：
图片传送门
只开O1,O2,O3：
图片传送门
只开GCC优化：
图片传送门
只开G++优化：
图片传送门
全开：
图片传送门
可见这其中巨大的差距，从不开优化的115耗时，到全开的10耗时，这差距，不用我说，大家也知道有多大吧，现在，在各大家打一遍 终极优化:
#pragma GCC optimize(1)
#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")
#pragma G++ optimize(1)
#pragma G++ optimize(2)
#pragma G++ optimize(3)
#pragma G++ optimize("Ofast")
#pragma G++ optimize("inline")
#pragma G++ optimize("-fgcse")
#pragma G++ optimize("-fgcse-lm")
#pragma G++ optimize("-fipa-sra")
#pragma G++ optimize("-ftree-pre")
#pragma G++ optimize("-ftree-vrp")
#pragma G++ optimize("-fpeephole2")
#pragma G++ optimize("-ffast-math")
#pragma G++ optimize("-fsched-spec")
#pragma G++ optimize("unroll-loops")
#pragma G++ optimize("-falign-jumps")
#pragma G++ optimize("-falign-loops")
#pragma G++ optimize("-falign-labels")
#pragma G++ optimize("-fdevirtualize")
#pragma G++ optimize("-fcaller-saves")
#pragma G++ optimize("-fcrossjumping")
#pragma G++ optimize("-fthread-jumps")
#pragma G++ optimize("-funroll-loops")
#pragma G++ optimize("-fwhole-program")
#pragma G++ optimize("-freorder-blocks")
#pragma G++ optimize("-fschedule-insns")
#pragma G++ optimize("inline-functions")
#pragma G++ optimize("-ftree-tail-merge")
#pragma G++ optimize("-fschedule-insns2")
#pragma G++ optimize("-fstrict-aliasing")
#pragma G++ optimize("-fstrict-overflow")
#pragma G++ optimize("-falign-functions")
#pragma G++ optimize("-fcse-skip-blocks")
#pragma G++ optimize("-fcse-follow-jumps")
#pragma G++ optimize("-fsched-interblock")
#pragma G++ optimize("-fpartial-inlining")
#pragma G++ optimize("no-stack-protector")
#pragma G++ optimize("-freorder-functions")
#pragma G++ optimize("-findirect-inlining")
#pragma G++ optimize("-frerun-cse-after-loop")
#pragma G++ optimize("inline-small-functions")
#pragma G++ optimize("-finline-small-functions")
#pragma G++ optimize("-ftree-switch-conversion")
#pragma G++ optimize("-foptimize-sibling-calls")
#pragma G++ optimize("-fexpensive-optimizations")
#pragma G++ optimize("-funsafe-loop-optimizations")
#pragma G++ optimize("inline-functions-called-once")
#pragma G++ optimize("-fdelete-null-pointer-checks")
记住，优化打在代码（头文件）之前
记住，这是专属于c++的终极优化代码
禁：这些代码，只能放在c++，不然，在其他语言（包括c）就会编译错误或成为负优化；
编译错误：
编译链接错误(语法错误); 编译链接错误又分成编译错和链接错。 编译错就是普通意义上的语
法错,编译器进行语法检查不通过,也就是程序违背了计算机语言的语法,例如:括号不匹配、变量
名拼写错误、用保留字定义变量名等; 链接错是指程序通过了语法检查,但是无法生成可执行文
件,最常见的是链接找不到。这里文件与连接又称变量。
下面，给大家一个链接，这个链接时关于o1,o2,o3的专属讲解：
点我去讲解
另外，注意，这些优化千万不要放到考试或比赛里面去用，这些优化比赛，考试禁用，只在平常刷提超时时就可以了，
这些代码不用呗，代码不是通用的，但是头优化是通用的，只要点进来复制一下我打的这一大段优化就行，再给大家
看看，这些优化打哪里：
框架代码之前，都可放置（点我看图片）
下面，便是改后的终极优化代码：
#pragma GCC optimize(1)
#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")
#pragma G++ optimize(1)
#pragma G++ optimize(2)
#pragma G++ optimize(3)
#pragma G++ optimize("Ofast")
#pragma G++ optimize("inline")
#pragma G++ optimize("-fgcse")
#pragma G++ optimize("-fgcse-lm")
#pragma G++ optimize("-fipa-sra")
#pragma G++ optimize("-ftree-pre")
#pragma G++ optimize("-ftree-vrp")
#pragma G++ optimize("-fpeephole2")
#pragma G++ optimize("-ffast-math")
#pragma G++ optimize("-fsched-spec")
#pragma G++ optimize("unroll-loops")
#pragma G++ optimize("-falign-jumps")
#pragma G++ optimize("-falign-loops")
#pragma G++ optimize("-falign-labels")
#pragma G++ optimize("-fdevirtualize")
#pragma G++ optimize("-fcaller-saves")
#pragma G++ optimize("-fcrossjumping")
#pragma G++ optimize("-fthread-jumps")
#pragma G++ optimize("-funroll-loops")
#pragma G++ optimize("-fwhole-program")
#pragma G++ optimize("-freorder-blocks")
#pragma G++ optimize("-fschedule-insns")
#pragma G++ optimize("inline-functions")
#pragma G++ optimize("-ftree-tail-merge")
#pragma G++ optimize("-fschedule-insns2")
#pragma G++ optimize("-fstrict-aliasing")
#pragma G++ optimize("-fstrict-overflow")
#pragma G++ optimize("-falign-functions")
#pragma G++ optimize("-fcse-skip-blocks")
#pragma G++ optimize("-fcse-follow-jumps")
#pragma G++ optimize("-fsched-interblock")
#pragma G++ optimize("-fpartial-inlining")
#pragma G++ optimize("no-stack-protector")
#pragma G++ optimize("-freorder-functions")
#pragma G++ optimize("-findirect-inlining")
#pragma G++ optimize("-frerun-cse-after-loop")
#pragma G++ optimize("inline-small-functions")
#pragma G++ optimize("-finline-small-functions")
#pragma G++ optimize("-ftree-switch-conversion")
#pragma G++ optimize("-foptimize-sibling-calls")
#pragma G++ optimize("-fexpensive-optimizations")
#pragma G++ optimize("-funsafe-loop-optimizations")
#pragma G++ optimize("inline-functions-called-once")
#pragma G++ optimize("-fdelete-null-pointer-checks")
写了这么多，还请各位大佬给我点个赞