输入输出优化

每天看看同学的程序还是有很多收获的，比如今天template

#include<bits/stdc++.h>

typedef long long ll;
ll n;

template<typename T> T read() {
    T n(0), f(1);
    char ch = getchar();
    for( ;!isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
    for( ; isdigit(ch); ch = getchar()) n = n * 10 + ch - 48; 
    return n * f;
}

inline void write(ll re){
    if(re < 0){
        putchar('-');
        re = -re;
    }
    if(re > 9) write(re/10);
    putchar(re%10+'0');
}

int main(){
	n = read<ll>();
	write(n);
	printf("\n");
	return 0;
}