View Compilation Error

0_0_38084304_16493.cpp:4:2: error: 'string' does not name a type
  string s;
  ^
0_0_38084304_16493.cpp: In function 'int main()':
0_0_38084304_16493.cpp:18:18: error: 'struct arr' has no member named 's'
    cin >> str[i].s;
                  ^
0_0_38084304_16493.cpp:25:16: error: 'struct arr' has no member named 's'
     if (str[i].s == str[j].s)
                ^
0_0_38084304_16493.cpp:25:28: error: 'struct arr' has no member named 's'
     if (str[i].s == str[j].s)
                            ^
0_0_38084304_16493.cpp:28:13: error: 'struct arr' has no member named 's'
      str[j].s = '\0';
             ^
0_0_38084304_16493.cpp:37:18: error: 'struct arr' has no member named 's'
   cout << str[d].s<<endl;
                  ^