Compilare: main.cpp: In function 'bool compare(wow, wow)': main.cpp:17:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<val.size();i++) ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:56:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<val.size();j++) ~^~~~~~~~~~~ main.cpp:68:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<val.size();j++) ~^~~~~~~~~~~ main.cpp:102:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<val.size();j++) ~^~~~~~~~~~~