/in/foo.c: In function 'main':
/in/foo.c:13:28: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   13 |                         if(i=j)
      |                            ^
/in/foo.c:19:42: warning: array subscript -1 is below array bounds of 'int[20][20]' [-Warray-bounds]
   19 |                                 a[i][j]=a[i-1][j]+a[i-1][j-1];
      |                                         ~^~~~~
/in/foo.c:5:10: note: while referencing 'a'
    5 |    int n,a[20][20],i,j;
      |          ^
/in/foo.c:19:57: warning: array subscript -1 is below array bounds of 'int[20]' [-Warray-bounds]
   19 |                                 a[i][j]=a[i-1][j]+a[i-1][j-1];
      |                                                   ~~~~~~^~~~~
/in/foo.c:5:10: note: while referencing 'a'
    5 |    int n,a[20][20],i,j;
      |          ^