Compilare: main.cpp: In function 'int main()': main.cpp:107:13: warning: unused variable 'val' [-Wunused-variable] int val = v1.back(); ^~~ main.cpp:81:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tvshow.in", "r", stdin); ^ main.cpp:82:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("tvshow.out", "w", stdout); ^ main.cpp:84:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:86:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a[i].x, &a[i].p); ^ main.cpp:95:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X); ^