View Compilation Error

0_0_25241207_22646.cpp: In function 'int ask(int, int, int)':
0_0_25241207_22646.cpp:19:18: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    else if(vis==-1&&mp[i].find(d)!=mp[i].end()) ans+=mp[i][d];
                  ^