Compilare: user.cpp: In function ‘void read()’: user.cpp:12:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:12:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘void roy_floyd()’: user.cpp:25:59: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(i!=j && matrice[i][k] && matrice[k][j] && (matrice[i][j] > matrice[i][k]+matrice[k][j]) || !matrice[i][j] ) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:21:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j,k; ^ user.cpp:21:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,k; ^ user.cpp:21:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k; ^ user.cpp: In function ‘void read()’: user.cpp:10:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("royfloyd.in","r",stdin); ^ user.cpp:11:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("royfloyd.out","w",stdout); ^ user.cpp:13:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:16:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&matrice[i][j]); ^