卡常技巧

快读

inline int read()
{
	int x=0,f=1;char ch=getchar_unlocked();
	for(;ch<'0'||ch>'9';ch=getchar_unlocked())if(ch=='-')f=-1;
	for(;ch>='0'&&ch<='9';ch=getchar_unlocked())x=(x<<3)+(x<<1)+(ch^48);
	return x*f;	
}

快写

inline void write(int x)
{
	return x<0?(putchar_unlocked('-'),write(-x),void(0)):(x==0?void(0):(write(x/10),putchar_unlocked((x%10)|48),void(0)));
}

诸如此类__builtin_printf,__builtin_scanf还有解绑\(cin,cout\),#define speed() ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);

三目运算符,优化\(if\)语句(条件)?op1:op2
卡常题U438090 [SUMMER STU] First Zero (Hard Version)

#include <bits/stdc++.h>
#define speed() ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
#define ll long long
#define pb push_back
#define ull unsigned long long
#define pii pair<int,int>
#define lid (rt<<1)
#define rid (rt<<1|1)
using namespace std;
const int N = 5e6+5;
int n,pre[N],nxt[N];
inline int read()
{
	int x=0,f=1;char ch=getchar_unlocked();
	for(;ch<'0'||ch>'9';ch=getchar_unlocked())if(ch=='-')f=-1;
	for(;ch>='0'&&ch<='9';ch=getchar_unlocked())x=(x<<3)+(x<<1)+(ch^48);
	return x*f;	
}
inline void write(int x)
{
	return x?write(x/10),putchar_unlocked((x%10)|'0'),void(0):void(0);
}
int main()
{
    // freopen("in.in","r",stdin);
    // freopen("out.out","w",stdout);
    register int pos;
  	n=read();
    for(register int i=1;i<=n+1;i=-~i)pre[i]|=i-1,nxt[i]|=i+1;
    for(register int i=1;i<=n-1;i=-~i)
    {
    	pos=read();
    	nxt[pre[pos]]=nxt[pos];
    	pre[nxt[pos]]=pre[pos];
    	nxt[pos]==n+1?(putchar('-'),putchar('1'),void(0)):(write(nxt[pos]));
    	putchar_unlocked('\n');
    	// __builtin_printf("%d\n",(nxt[pos]==n+1?-1:nxt[pos]));
    }
	return 0;
}

火车头

点击查看代码

#pragma GCC optimize(3)
#pragma GCC target("avx,sse2,sse3,sse4,mmx")
#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("-fhoist-adjacent-loads")
#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")