Compilare: main.cpp: In function 'int main()': main.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1;i<=n;i++) ~^~~ main.cpp:31:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1 ;i<=n;i++) ~^~~ main.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 2;i<=n;i++) ~^~~ main.cpp:38:9: warning: variable 'end' set but not used [-Wunused-but-set-variable] int end=1,start=1; ^~~ main.cpp:38:15: warning: variable 'start' set but not used [-Wunused-but-set-variable] int end=1,start=1; ^~~~~