C++快速读入优化技巧

快读

#ifdef__unix__#definegcgetchar_unlocked#else#definegc_getchar_nolock#endifinlineintread(){intx=0,f=1;charc=gc();while(c<'0'||c>'9'){if(c=='-')f=-1;c=gc();}while(c>='0'&&c<='9'){x=(x<<3)+(x<<1)+(c-'0');c=gc();}returnx*f;}

P10815 【模板】快速读入

#include<cstdio>#include<cstring>#include<algorithm>usingnamespacestd;typedeflonglongll;inlineintread(){intx=0;charc=getchar_unlocked(),cc=' ';while(c>'9'||c<'0')cc=c,c=getchar_unlocked();while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar_unlocked();returncc=='-'?-x:x;}intmain(){intn=read();intsum0=0,sum1=0,sum2=0,sum3=0,sum4=0,sum5=0,sum6=0,sum7=0,x,i;for(i=1;i+8<=n;i+=8){x=read();sum0+=x;x=read();sum1+=x;x=read();sum2+=x;x=read();sum3+=x;x=read();sum4+=x;x=read();sum5+=x;x=read();sum6+=x;x=read();sum7+=x;}for(;i<=n;i++){x=read();sum0+=x;}printf("%d",sum0+sum1+sum2+sum3+sum4+sum5+sum6+sum7);return0;}