Compilare: main.cpp: In function 'void backtrack(int, int)': main.cpp:29:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos<sum[linie].size()/4) ~~~^~~~~~~~~~~~~~~~~~~~ main.cpp:31:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(pos<sum[linie].size()/2) ~~~^~~~~~~~~~~~~~~~~~~~ main.cpp:33:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(pos<3*(sum[linie].size()/4)) ~~~^~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:37:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sum[linie-1].size();i++) ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:73:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<sum[i-1].size();k++) ~^~~~~~~~~~~~~~~~