Compilare: main.cpp: In function 'void solve(int, int, int, int)': main.cpp:9:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] { if(k==lucru.size()) return ; ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:41:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:55:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~