Compilare: main.cpp: In function 'int main()': main.cpp:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) ~~^~~~~~~~~~ main.cpp:24:9: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized] if (a[i] > x) { ^~