Compilare: main.cpp: In function 'int main()': main.cpp:12:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s)-1;i++) ~^~~~~~~~~~~~~ main.cpp:13:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {if(i<strlen(s)-1) ~^~~~~~~~~~~~ main.cpp:21:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==strlen(s)-1) ~^~~~~~~~~~~~~ main.cpp:21:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(i==strlen(s)-1) ^