c++ 读入的测试

#include <bits/stdc++.h>
int main(){
    freopen("num.txt","r",stdin);
    int a;
    for(int i=1;i<=10000000;i++) std::cin>>a;
    return 0;
} 

#include <bits/stdc++.h>

int main(){
    freopen("string.txt","r",stdin);
    char a;
    for(int i=1;i<=10000000;i++) std::cin>>a;
    
    return 0;
} 

#include <bits/stdc++.h>
int main(){
    freopen("string.txt","r",stdin);
    std::string st;
    std::cin>>st; 
    return 0;
} 

#include <bits/stdc++.h>
using namespace std;
int main(){
    freopen("string.txt","r",stdin);
    sync_with_stdio(false);
    char a;
    for(int i=1;i<=50000000;i++) cin>>a;
    return 0;
} 

#include <bits/stdc++.h>
using namespace std;
int main(){
    freopen("num.txt","r",stdin);
    int a;
    for(int i=1;i<=10000000;i++) scanf("%d",&a);
    return 0;
} 

#include <bits/stdc++.h>
using namespace std;
int read(){  
    int x=0; char ch=getchar();  
    while (ch<‘0‘ || ch>‘9‘) ch=getchar();  
    while (ch>=‘0‘ && ch<=‘9‘){ x=x*10+ch-‘0‘; ch=getchar(); }  
    return x; 
}
int main(){
    freopen("num.txt","r",stdin);
    int a;
    for(int i=1;i<=10000000;i++) a=read();
    return 0;
} 

#include <bits/stdc++.h> 
const int MAXS = 60*1024*1024;

int numbers[10001000];
char buf[MAXS];

void read(char *buf,int len = MAXS){
    int i;
    numbers[i=0]=0;
    for (char *p=buf;*p && p-buf<len;p++)
        if (*p == ‘ ‘)
            numbers[++i]=0;
        else
            numbers[i] = numbers[i] * 10 + *p - ‘0‘;
} 

int main(){
    freopen("num.txt","rb",stdin);
    int len = fread(buf,1,MAXS,stdin);
    buf[len] = ‘/0‘;
    read(buf,len);
}