Compilare: user.cpp: In function ‘int solve(int*, int, int, int)’: user.cpp:15:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, s; ^ user.cpp: In function ‘int main()’: user.cpp:44:12: warning: unused variable ‘m’ [-Wunused-variable] int n, m, i, j, k, sa, sb, xi, yi, xf, yf, sol, ans; ^ user.cpp:44:18: warning: unused variable ‘j’ [-Wunused-variable] int n, m, i, j, k, sa, sb, xi, yi, xf, yf, sol, ans; ^ user.cpp:44:48: warning: unused variable ‘sol’ [-Wunused-variable] int n, m, i, j, k, sa, sb, xi, yi, xf, yf, sol, ans; ^ user.cpp:44:53: warning: unused variable ‘ans’ [-Wunused-variable] int n, m, i, j, k, sa, sb, xi, yi, xf, yf, sol, ans; ^ user.cpp:41:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pipe.in","r",stdin); ^ user.cpp:42:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pipe.out","w",stdout); ^ user.cpp:49:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d%d%d%d",&n,&xi,&yi,&xf,&yf ); ^ user.cpp:52:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%*c%c%d",&c,&k ); ^