View Compilation Error

0_0_33338587_15406.cpp: In function 'int main()':
0_0_33338587_15406.cpp:15:15: error: 'last' was not declared in this scope
        memset(last,0,sizeof(last));
               ^
0_0_33338587_15406.cpp:22:35: error: 't' was not declared in this scope
            if(last[x]==0||last[x]<t) {
                                   ^
0_0_33338587_15406.cpp:26:12: error: 'ans' was not declared in this scope
            ans++;
            ^
0_0_33338587_15406.cpp:27:12: error: 't' was not declared in this scope
            t=i;
            ^
0_0_33338587_15406.cpp:30:14: error: 'ans' was not declared in this scope
        cout<<ans<<endl;
              ^