Compilare: main.cpp: In function 'int main()': main.cpp:110:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ~^~~~~~~~~ main.cpp:119:13: warning: unused variable 'a' [-Wunused-variable] int a,b,c; ^ main.cpp:119:15: warning: unused variable 'b' [-Wunused-variable] int a,b,c; ^ main.cpp:119:17: warning: unused variable 'c' [-Wunused-variable] int a,b,c; ^