輸入兩個文件名，依次各自讀取字符串並比較，如果不同，輸出不同處的序號和各自的內容

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define rep(i,a,b) for(int i=a;i<=b;++i)
 4 #define ms(arr,a) memset(arr,a,sizeof arr)
 5 #define debug(x) cout<<"< "#x" = "<<x<<" >"<<endl
 6 int main()
 7 {
 8     ifstream f1,f2;
 
 9     char f1name[100],f2name[100];
10     const int maxn=1e5;
11     char s1[maxn],s2[maxn];
12     cin>>f1name>>f2name;
13     f1.open(f1name);f2.open(f2name);
14     for(int i=1;!f1.eof();++i)
15     {
16         if(f2.eof())
17         {
18             cout<<f2name<<" is smaller than 
 
"<<f1name<<endl;
19             break;
20         }
21         f1>>s1;f2>>s2;
22         if(strcmp(s1,s2))cout<<i<<": "<<s1<<" "<<s2<<endl;
23     }
24     if(!f2.eof())cout<<f1name<<" is smaller than "<<f2name<<endl;
 
25 }

#工具：文件比較