Compilare: user.cpp: In function ‘void roy_floyd()’: user.cpp:24:88: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if((a[i][k]+a[k][j]<a[i][j] || !a[i][j] || a[i][k]+a[k][j]<a[i][j] && t[i][j]<t[i][k]+t[k][j]) && i!=j) ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘void read()’: user.cpp:9:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:12:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&a[i][j]); ^