Compilare: user.cpp: In function ‘int main()’: user.cpp:26:53: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(a[i][j]>a[i][k]+a[k][j]||!a[i][j]&&i!=j) ~~~~~~~~^~~~~~ user.cpp:18:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:21:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d ",&a[i][j]); ^