Compilare: main.cpp: In function 'Int operator+(Int, Int)': main.cpp:31:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0, t = 0; i < a.size() || i < b.size() || t; i++, t /= 10) { ~~^~~~~~~~~~ main.cpp:31:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0, t = 0; i < a.size() || i < b.size() || t; i++, t /= 10) { ~~^~~~~~~~~~ main.cpp:32:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < a.size()) ~~^~~~~~~~~~ main.cpp:34:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < b.size()) ~~^~~~~~~~~~ main.cpp: In function 'Int operator*(Int, Int)': main.cpp:44:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size(); i++) { ~~^~~~~~~~~~ main.cpp:46:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < b.size() || t; j++, t /= 10) { ~~^~~~~~~~~~ main.cpp:48:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j < b.size()) ~~^~~~~~~~~~