Compilare: main.cpp: In function 'int main()': main.cpp:11:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a.length() && j<b.length()) ~^~~~~~~~~~~ main.cpp:11:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a.length() && j<b.length()) ~^~~~~~~~~~~ main.cpp:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(x<a.length() && y<b.length() && a[x]==b[y]) ~^~~~~~~~~~~ main.cpp:15:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(x<a.length() && y<b.length() && a[x]==b[y]) ~^~~~~~~~~~~ main.cpp:20:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(y==b.length() || (x<a.length() && a[x]>b[y])) ~^~~~~~~~~~~~ main.cpp:20:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(y==b.length() || (x<a.length() && a[x]>b[y])) ~^~~~~~~~~~~ main.cpp:31:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a.length()) ~^~~~~~~~~~~ main.cpp:36:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<b.length()) ~^~~~~~~~~~~