Compilare: user.cpp: In function ‘int main()’: user.cpp:25:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(y=0;y<sum[key].size();y++) ^ user.cpp:43:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sum[i].size();j++) ^ user.cpp:48:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(y=0;y<sum[key].size();y++) ^ user.cpp:15:13: warning: unused variable ‘x’ [-Wunused-variable] int num,x,y,n,a[102],s,key; ^ user.cpp:58:9: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(l) ^