Compilare: main.cpp: In function 'int solve(int, int)': main.cpp:12:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (index == x.size() / 2 + 1) ~~~~~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:65:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= (x.size() - 1) / 2; ++i) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:78:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < x.size(); ++i) ~~^~~~~~~~~~ main.cpp:85:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= x.size() / 2 + 4; ++i) ~~^~~~~~~~~~~~~~~~~~~ main.cpp:89:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= x.size() / 2 + 1; ++i) ~~^~~~~~~~~~~~~~~~~~~ main.cpp:120:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= x.size() / 2; ++i) ~~^~~~~~~~~~~~~~~ main.cpp:125:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= x.size(); ++i) ~~^~~~~~~~~~~