技巧总结

快读：

取消输入输出缓存

ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);

---

普通快读：

inline int read()
{
    int x=0,c=getchar(),f=0;
    for(;c>'9'||c<'0';f=c=='-',c=getchar());
    for(;c>='0'&&c<='9';c=getchar())
    x=(x<<1)+(x<<3)+(c^48);
	return f?-x:x;
}
inline void write(int x)
{	
	x<0?(putchar('-'),x=-x):1;
    if(x>9)  write(x/10);
    putchar(x%10+'0');
}

---

快到起飞！！！

#define getchar()                                                              \
    (tt == ss && (tt=(ss=In)+fread(In, 1, 1 << 20, stdin), ss == tt)     \
         ? EOF                                                                 \
         : *ss++)
char In[1<<20],*ss=In,*tt=In;
inline int read()
{
	int x=0,f=1;char c=getchar();
	while(c>'9'||c<'0'){if(c=='-')f=-1;c=getchar();}
	while(c>='0'&&c<='9'){x=(x<<1)+(x<<3)+(c^48);c=getchar();}
	return x*f;
}
inline void write(int x)
{
    if(x<0)x=(~x+1),putchar('-');
    if(x>9)write(x/10);
    putchar(x%10+'0');
}

---

namespace IN{//快读
    const int MAX_INPUT = 1000000;
    #define getc() (p1==p2&&(p2=(p1=buf)+inbuf->sgetn(buf,MAX_INPUT),p1==p2)?EOF:*p1++)
    char buf[MAX_INPUT],*p1,*p2;
    template<typename T>inline bool read(T &x) {
        static std::streambuf *inbuf=cin.rdbuf();
        x=0;
        register int f=0,flag=false;
        register char ch=getc();
        while(!isdigit(ch)){
            if (ch=='-') f=1;
        	ch=getc();
        }
        if(isdigit(ch)) x=x*10+ch-'0',ch=getc(),flag=true;
        while(isdigit(ch)) {
            x=x*10+ch-48;
            ch=getc();
        }
        x=f?-x:x;
        return flag;
    }
    template<typename T,typename ...Args>inline bool read(T& a,Args& ...args) {
       return read(a)&&read(args...);
    }
    #undef getc
}

namespace OUT{//快写
    template<typename T>inline void put(T x){
        static std::streambuf *outbuf=cout.rdbuf();
        static char stack[21];
        static int top=0;
        if(x<0){
            outbuf->sputc('-');
            x=-x;
        }
        if(!x){
            outbuf->sputc('0');
            outbuf->sputc('\n');
            return;
        }
        while(x){
            stack[++top]=x%10+'0';
            x/=10;
        }
        while(top){
            outbuf->sputc(stack[top]);
            --top;
        }
        outbuf->sputc('\n');
    }
    inline void putc(const char ch){
        static std::streambuf *outbuf=cout.rdbuf();
        outbuf->sputc(ch);
    }
    inline void putstr(string s){
    	for(register int i=0;i<s.length();i++) putc(s[i]);
	}
    template<typename T>inline void put(const char ch,T x){
        static std::streambuf *outbuf=cout.rdbuf();
        static char stack[21];
        static int top = 0;
        if(x<0){
            outbuf->sputc('-');
            x=-x;
        }
        if(!x){
            outbuf->sputc('0');
            outbuf->sputc(ch);
            return;
        }
        while(x){
            stack[++top]=x%10+'0';
            x/=10;
        }
        while(top){
            outbuf->sputc(stack[top]);
            --top;
        }
        outbuf->sputc(ch);
    }
    template<typename T,typename ...Args> inline void put(T a,Args ...args){
        put(a);put(args...);
    }
    template<typename T,typename ...Args> inline void put(const char ch,T a,Args ...args){
        put(ch,a);put(ch,args...);
    }
}
using IN::read;
using OUT::put;
using OUT::putc;
using OUT::putstr;

卡常火车头：

#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("-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")

颜色封装函数

void Color(int a)//颜色封装函数 
{
	/*
	* 0 — 白色
	* 1 — 浅蓝 
	* 2 — 绿色 
	* 3 — 紫色 
	* 4 — 红色 
	* 5 — 黄色 
	* 6 — 深蓝 
	* 7 — 还原（浅灰） 
	* 8 — 深红 
	* 9 — 背景-浅蓝 
	* 10 — 背景-紫色 
	* 11 — 深紫 
	* 12 — 深黄 
	* 13 — 灰色 
	* 14 — 蓝绿 
	*/
	if(a==0) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_BLUE);   //白色 
	if(a==1) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_GREEN|FOREGROUND_BLUE);   //浅蓝 
	if(a==2) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_GREEN);   //绿色 
	if(a==3) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_RED|FOREGROUND_BLUE);   //紫色 
	if(a==4) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_RED);   //红色 
	if(a==5) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_RED|FOREGROUND_GREEN);   //黄色 
	if(a==6) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY|FOREGROUND_BLUE);   //深蓝 
	if(a==7) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_RED|FOREGROUND_GREEN|FOREGROUND_BLUE);   //还原（浅灰） 
	if(a==8) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_RED);   //深红 
	if(a==9) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY|BACKGROUND_GREEN|BACKGROUND_BLUE);   //背景-浅蓝 
	if(a==10) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY|BACKGROUND_RED|BACKGROUND_BLUE);   //背景-紫色 
	if(a==11) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_RED|FOREGROUND_BLUE);   //深紫 
	if(a==12) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_RED|FOREGROUND_GREEN);   //深黄 
	if(a==13) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY);   //灰色 
	if(a==14) SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_GREEN|FOREGROUND_BLUE);   //蓝绿 
}