Compilare: main.cpp: In function 'int getMex(std::vector<int>&)': main.cpp:41:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i >= vals.size() || vals[i] != i) return i; ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:67:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("game4.in", "r", stdin); ^ main.cpp:68:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("game4.out", "w", stdout); ^ main.cpp:72:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &t, &c); ^ main.cpp:89:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:91:54: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(int i = 0; i < n; ++i) scanf("%d", &v), desc(v); ^