快读快写

1

int read() {
    char c=getchar();while(!isdigit(c)) c=getchar();
    int num=0;while(isdigit(c)) num=num*10+c-'0',c=getchar();
    return num;
}

inline int read(){
    int res=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-') f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') res=res*10+ch-'0',ch=getchar();
    return res*f;
}
inline void write(int x){
    if(x<0) putchar('-'),x=-x;
    if(x<10) putchar(x+'0');
    else{
        write(x/10);
        putchar(x%10+'0');
    }
}

感觉用处不大嫌麻烦记不住，没用过，一直用2

2

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

简单清爽，cin和cout基本和scanf,printf差不多快，循环中的读入和输出如果怕TLE还是用scanf,printf

3

void sc(int& x) { scanf("%d", &x); }

void sc(int64_t& x) { scanf("%lld", &x); }

void sc(double& x) { scanf("%lf", &x); }

void sc(char& x) { scanf(" %c", &x); }

void sc(char* x) { scanf("%s", x); }

整一堆函数上去，读入直接sc(x);