View Compilation Error

0_0_17137157_648.cpp: In function 'int main()':
0_0_17137157_648.cpp:38:3: error: '_int64' was not declared in this scope
   _int64 ans=0;
   ^
0_0_17137157_648.cpp:45:4: error: 'ans' was not declared in this scope
    ans+=get(a[i]-1);//a[i]前面比a[i]小的数的和
    ^
0_0_17137157_648.cpp:53:22: error: 'ans' was not declared in this scope
     printf("%I64d\n",ans);
                      ^
0_0_17137157_648.cpp:64:7: error: 'ans' was not declared in this scope
       ans--;
       ^
0_0_17137157_648.cpp:66:7: error: 'ans' was not declared in this scope
       ans++;
       ^