我的读入挂：

namespace FastIO { const int SIZE = 1 << 16; char buf[SIZE], str[64]; int l = SIZE, r = SIZE; int read(char *s) { while (r) { for (; l < r && buf[l] <= ' '; l++); if (l < r) break; l = 0, r = int(fread(buf, 1, SIZE, stdin)); } int cur = 0; while (r) { for (; l < r && buf[l] > ' '; l++) s[cur++] = buf[l]; if (l < r) break; l = 0, r = int(fread(buf, 1, SIZE, stdin)); } s[cur] = '\0'; return cur; } template<typename type> bool read(type &x, int len = 0, int cur = 0, bool flag = false) { if (!(len = read(str))) return false; if (str[cur] == '-') flag = true, cur++; for (x = 0; cur < len; cur++) x = x * 10 + str[cur] - '0'; if (flag) x = -x; return true; } template <typename type> type read(int len = 0, int cur = 0, bool flag = false, type x = 0) { if (!(len = read(str))) return false; if (str[cur] == '-') flag = true, cur++; for (x = 0; cur < len; cur++) x = x * 10 + str[cur] - '0'; return flag ? -x : x; } } using FastIO::read; int main() { char str[107]; read(str); printf("read(char *): %s\n", str); int n = read<int>(); printf("read<int>() = %d\n", n); read(n); printf("read(n), n = %d\n", n); long long m = read<long long>(); printf("read<long long>() = %lld\n", m); read(m); printf("read(m), m = %lld\n", m); while (read(n)) printf("%d\n", n); return 0; }

  Fread读入挂会不断的将控制台的内容读入缓存，直到读入末尾EOF才会停止读入，故常规情况无法测试，推荐使用freopen。

qscqesze大佬的读入挂：

http://www.cnblogs.com/qscqesze/p/5736748.html

fread读入挂：

const int BUF=40000000; char Buf[BUF],*buf=Buf; const int OUT=20000000; char Out[OUT],*ou=Out;int Outn[30],Outcnt; inline void write(int x){ if(!x)*ou++=48; else{ for(Outcnt=0;x;x/=10)Outn[++Outcnt]=x%10+48; while(Outcnt)*ou++=Outn[Outcnt--]; } } inline void writell(ll x){ if(!x)*ou++=48; else{ for(Outcnt=0;x;x/=10)Outn[++Outcnt]=x%10+48; while(Outcnt)*ou++=Outn[Outcnt--]; } } inline void writechar(char x){*ou++=x;} inline void writeln(){*ou++='\n';} inline void read(int&a){for(a=0;*buf<48;buf++);while(*buf>47)a=a*10+*buf++-48;} //这句话放到代码中 fread(Buf,1,BUF,stdin); //样例 #include<bits/stdc++.h> using namespace std; typedef long long ll; const int BUF=40000000; char Buf[BUF],*buf=Buf; const int OUT=20000000; char Out[OUT],*ou=Out;int Outn[30],Outcnt; inline void write(int x){ if(!x)*ou++=48; else{ for(Outcnt=0;x;x/=10)Outn[++Outcnt]=x%10+48; while(Outcnt)*ou++=Outn[Outcnt--]; } } inline void writell(ll x){ if(!x)*ou++=48; else{ for(Outcnt=0;x;x/=10)Outn[++Outcnt]=x%10+48; while(Outcnt)*ou++=Outn[Outcnt--]; } } inline void writechar(char x){*ou++=x;} inline void writeln(){*ou++='\n';} inline void read(int&a){for(a=0;*buf<48;buf++);while(*buf>47)a=a*10+*buf++-48;} int main(){ fread(Buf,1,BUF,stdin); int a,b; read(a),read(b); write(a+b); writeln(); fwrite(Out,1,ou-Out,stdout); }

一般读入挂：

inline ll read() { int x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; }

超神读入挂：

namespace fastIO{ #define BUF_SIZE 100000 #define OUT_SIZE 100000 #define ll long long //fread->read bool IOerror=0; inline char nc(){ static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE; if (p1==pend){ p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin); if (pend==p1){IOerror=1;return -1;} //{printf("IO error!\n");system("pause");for (;;);exit(0);} } return *p1++; } inline bool blank(char ch){return ch==' '||ch=='\n'||ch=='\r'||ch=='\t';} inline void read(int &x){ bool sign=0; char ch=nc(); x=0; for (;blank(ch);ch=nc()); if (IOerror)return; if (ch=='-')sign=1,ch=nc(); for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; if (sign)x=-x; } inline void read(ll &x){ bool sign=0; char ch=nc(); x=0; for (;blank(ch);ch=nc()); if (IOerror)return; if (ch=='-')sign=1,ch=nc(); for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; if (sign)x=-x; } inline void read(double &x){ bool sign=0; char ch=nc(); x=0; for (;blank(ch);ch=nc()); if (IOerror)return; if (ch=='-')sign=1,ch=nc(); for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0'; if (ch=='.'){ double tmp=1; ch=nc(); for (;ch>='0'&&ch<='9';ch=nc())tmp/=10.0,x+=tmp*(ch-'0'); } if (sign)x=-x; } inline void read(char *s){ char ch=nc(); for (;blank(ch);ch=nc()); if (IOerror)return; for (;!blank(ch)&&!IOerror;ch=nc())*s++=ch; *s=0; } inline void read(char &c){ for (c=nc();blank(c);c=nc()); if (IOerror){c=-1;return;} } //getchar->read inline void read1(int &x){ char ch;int bo=0;x=0; for (ch=getchar();ch<'0'||ch>'9';ch=getchar())if (ch=='-')bo=1; for (;ch>='0'&&ch<='9';x=x*10+ch-'0',ch=getchar()); if (bo)x=-x; } inline void read1(ll &x){ char ch;int bo=0;x=0; for (ch=getchar();ch<'0'||ch>'9';ch=getchar())if (ch=='-')bo=1; for (;ch>='0'&&ch<='9';x=x*10+ch-'0',ch=getchar()); if (bo)x=-x; } inline void read1(double &x){ char ch;int bo=0;x=0; for (ch=getchar();ch<'0'||ch>'9';ch=getchar())if (ch=='-')bo=1; for (;ch>='0'&&ch<='9';x=x*10+ch-'0',ch=getchar()); if (ch=='.'){ double tmp=1; for (ch=getchar();ch>='0'&&ch<='9';tmp/=10.0,x+=tmp*(ch-'0'),ch=getchar()); } if (bo)x=-x; } inline void read1(char *s){ char ch=getchar(); for (;blank(ch);ch=getchar()); for (;!blank(ch);ch=getchar())*s++=ch; *s=0; } inline void read1(char &c){for (c=getchar();blank(c);c=getchar());} //scanf->read inline void read2(int &x){scanf("%d",&x);} inline void read2(ll &x){ #ifdef _WIN32 scanf("%I64d",&x); #else #ifdef __linux scanf("%lld",&x); #else puts("error:can't recognize the system!"); #endif #endif } inline void read2(double &x){scanf("%lf",&x);} inline void read2(char *s){scanf("%s",s);} inline void read2(char &c){scanf(" %c",&c);} inline void readln2(char *s){gets(s);} //fwrite->write struct Ostream_fwrite{ char *buf,*p1,*pend; Ostream_fwrite(){buf=new char[BUF_SIZE];p1=buf;pend=buf+BUF_SIZE;} void out(char ch){ if (p1==pend){ fwrite(buf,1,BUF_SIZE,stdout);p1=buf; } *p1++=ch; } void print(int x){ static char s[15],*s1;s1=s; if (!x)*s1++='0';if (x<0)out('-'),x=-x; while(x)*s1++=x%10+'0',x/=10; while(s1--!=s)out(*s1); } void println(int x){ static char s[15],*s1;s1=s; if (!x)*s1++='0';if (x<0)out('-'),x=-x; while(x)*s1++=x%10+'0',x/=10; while(s1--!=s)out(*s1); out('\n'); } void print(ll x){ static char s[25],*s1;s1=s; if (!x)*s1++='0';if (x<0)out('-'),x=-x; while(x)*s1++=x%10+'0',x/=10; while(s1--!=s)out(*s1); } void println(ll x){ static char s[25],*s1;s1=s; if (!x)*s1++='0';if (x<0)out('-'),x=-x; while(x)*s1++=x%10+'0',x/=10; while(s1--!=s)out(*s1); out('\n'); } void print(double x,int y){ static ll mul[]={1,10,100,1000,10000,100000,1000000,10000000,100000000, 1000000000,10000000000LL,100000000000LL,1000000000000LL,10000000000000LL, 100000000000000LL,1000000000000000LL,10000000000000000LL,100000000000000000LL}; if (x<-1e-12)out('-'),x=-x;x*=mul[y]; ll x1=(ll)floor(x); if (x-floor(x)>=0.5)++x1; ll x2=x1/mul[y],x3=x1-x2*mul[y]; print(x2); if (y>0){out('.'); for (size_t i=1;i<y&&x3*mul[i]<mul[y];out('0'),++i); print(x3);} } void println(double x,int y){print(x,y);out('\n');} void print(char *s){while (*s)out(*s++);} void println(char *s){while (*s)out(*s++);out('\n');} void flush(){if (p1!=buf){fwrite(buf,1,p1-buf,stdout);p1=buf;}} ~Ostream_fwrite(){flush();} }Ostream; inline void print(int x){Ostream.print(x);} inline void println(int x){Ostream.println(x);} inline void print(char x){Ostream.out(x);} inline void println(char x){Ostream.out(x);Ostream.out('\n');} inline void print(ll x){Ostream.print(x);} inline void println(ll x){Ostream.println(x);} inline void print(double x,int y){Ostream.print(x,y);} inline void println(double x,int y){Ostream.println(x,y);} inline void print(char *s){Ostream.print(s);} inline void println(char *s){Ostream.println(s);} inline void println(){Ostream.out('\n');} inline void flush(){Ostream.flush();} //puts->write char Out[OUT_SIZE],*o=Out; inline void print1(int x){ static char buf[15]; char *p1=buf;if (!x)*p1++='0';if (x<0)*o++='-',x=-x; while(x)*p1++=x%10+'0',x/=10; while(p1--!=buf)*o++=*p1; } inline void println1(int x){print1(x);*o++='\n';} inline void print1(ll x){ static char buf[25]; char *p1=buf;if (!x)*p1++='0';if (x<0)*o++='-',x=-x; while(x)*p1++=x%10+'0',x/=10; while(p1--!=buf)*o++=*p1; } inline void println1(ll x){print1(x);*o++='\n';} inline void print1(char c){*o++=c;} inline void println1(char c){*o++=c;*o++='\n';} inline void print1(char *s){while (*s)*o++=*s++;} inline void println1(char *s){print1(s);*o++='\n';} inline void println1(){*o++='\n';} inline void flush1(){if (o!=Out){if (*(o-1)=='\n')*--o=0;puts(Out);}} struct puts_write{ ~puts_write(){flush1();} }_puts; inline void print2(int x){printf("%d",x);} inline void println2(int x){printf("%d\n",x);} inline void print2(char x){printf("%c",x);} inline void println2(char x){printf("%c\n",x);} inline void print2(ll x){ #ifdef _WIN32 printf("%I64d",x); #else #ifdef __linux printf("%lld",x); #else puts("error:can't recognize the system!"); #endif #endif } inline void println2(ll x){print2(x);printf("\n");} inline void println2(){printf("\n");} #undef ll #undef OUT_SIZE #undef BUF_SIZE }; using namespace fastIO;

注意

  举个例子，现在有一个表达式，addedge(u,v);，一定要老老实实的写成这种形式：

#define read read() int u = read, v = read; addedge(u,v);

  不能追求简洁写成这种形式：

#define read read() addedge(read, read);

  虽然本地编译器跑起来没问题，但是有些OJ会WA，比如说POJ，POJ，和POJ。

注意

  一般情况下相比scanf来说，只有当读入量达到 105 10 5 才会有明显作用。虽然读入挂看起来很厉害，有时候能过掉一些卡常数的题，但还是推荐小伙伴们追求正解。