Compilare: user.cpp: In function ‘int main()’: user.cpp:17:79: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(a[i][k]!=0&&a[k][j]!=0&&(a[i][j]>a[i][k]+a[k][j]||a[i][j]==0&&i!=j)){ ^ user.cpp:8:10: warning: unused variable ‘c’ [-Wunused-variable] int i,j,c,n; ^ user.cpp:6:36: 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:7:38: 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); ^