Compilare: user.cpp: In function ‘int main()’: user.cpp:9:48: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] int n, m, x, y, i, j, aux, p1, p2, f1, f2, a; ^ user.cpp:7:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inter.in", "r", stdin); ^ user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inter.out", "w", stdout); ^ user.cpp:10:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:15:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:26:19: warning: ‘p2’ may be used uninitialized in this function [-Wmaybe-uninitialized] v[p1]=v[p2]; ^ user.cpp:25:18: warning: ‘p1’ may be used uninitialized in this function [-Wmaybe-uninitialized] aux=v[p1]; ^