Compilare: user.cpp: In function ‘int main()’: user.cpp:42:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < v[ x ].size(); ++i ){ ^ user.cpp:20:18: warning: unused variable ‘j’ [-Wunused-variable] int n, m, i, j, t, x, y, col, minim; ^ user.cpp:17:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("reinvent.in","r",stdin); ^ user.cpp:18:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("reinvent.out","w",stdout); ^ user.cpp:23:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&t); ^ user.cpp:25:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:32:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^