Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:22:5: warning: this ‘for’ clause does not guard... [-Wmisleading-indentation] for(l=0; (1<<l) <= K; ++l); --l; ^~~ user.cpp:22:33: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘for’ for(l=0; (1<<l) <= K; ++l); --l; ^~ user.cpp: In function ‘void write()’: user.cpp:50:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^