Compilare: main.cpp: In function 'int main()': main.cpp:20:27: warning: statement has no effect [-Wunused-value] a[i][j]>a[i][k]+a[k][j]; ~~~~~~~^~~~~~~~~~~~~~~~ main.cpp:15:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&a[i][j]); ^ main.cpp:13:18: warning: 'n' is used uninitialized in this function [-Wuninitialized] for(int i=1;i<=n;++i) ~^~~