Compilare: main.cpp: In function 'int main()': main.cpp:55:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:60:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i;j<s.size();j++) ~^~~~~~~~~ main.cpp:50:15: warning: unused variable 'x' [-Wunused-variable] int m, n, x, i, j, nr; ^