Compilare: main.cpp: In function 'int main()': main.cpp:14:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s);i++) ~^~~~~~~~~~ main.cpp:17:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i+1;j<strlen(s);j++) ~^~~~~~~~~~ main.cpp:21:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=j+1;k<strlen(s);k++) ~^~~~~~~~~~