Compilare: user.cpp: In function ‘int main()’: user.cpp:77:10: warning: statement has no effect [-Wunused-value] for(k;k<m;++k){ ^ user.cpp:24:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("robot3.in", "r", stdin); ^ user.cpp:25:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("robot3.out", "w", stdout); ^ user.cpp:26:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%hd%hd%hd%hd\n", &n,&m,&l,&c); ^ user.cpp:27:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,20002,stdin); ^ user.cpp:40:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:78:21: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] l1+=dx[com[k]]; ^