Compilare: main.cpp: In function 'void c2()': main.cpp:60:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nv.size(); i++) { ~~^~~~~~~~~~~ main.cpp:66:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nv.size(); i++) { ~~^~~~~~~~~~~ main.cpp:75:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nv.size() - 1; i++) { ~~^~~~~~~~~~~~~~~ main.cpp:90:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nv.size(); i++) { ~~^~~~~~~~~~~ main.cpp:94:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nv.size(); i++) { ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:109:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arc.in", "r", stdin); ^ main.cpp:110:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arc.out", "w", stdout); ^