Compilare: main.cpp: In function 'void insert(node*, int, int)': main.cpp:29:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(start == s.length()-1){ ~~~~~~^~~~~~~~~~~~~~~ main.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=start;i<s.length();i++){ ~^~~~~~~~~~~ main.cpp: In function 'void check(node*, int, int)': main.cpp:84:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=start;i<s.length();i++){ ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:115:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<s.length();j++){ ~^~~~~~~~~~~ main.cpp:123:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<s.length();j++){ ~^~~~~~~~~~~