/in/foo.cc: In function 'int main()':
/in/foo.cc:18:21: warning: array subscript is above array bounds [-Warray-bounds]
             a[a[x][3]][2]=i; a[i][2]=x;
               ~~~~~~^
/in/foo.cc:19:27: warning: array subscript is above array bounds [-Warray-bounds]
             a[i][3]=a[x][3]; a[x][3]=i;
                     ~~~~~~^
/in/foo.cc:19:19: warning: array subscript is above array bounds [-Warray-bounds]
             a[i][3]=a[x][3]; a[x][3]=i;
             ~~~~~~^
/in/foo.cc:19:36: warning: array subscript is above array bounds [-Warray-bounds]
             a[i][3]=a[x][3]; a[x][3]=i;
                              ~~~~~~^
/in/foo.cc:26:42: warning: array subscript is above array bounds [-Warray-bounds]
             a[i][2]=a[x][2]; a[a[x][2]][3]=i;
                              ~~~~~~~~~~~~^
/in/foo.cc:27:30: warning: array subscript is above array bounds [-Warray-bounds]
             a[x][2]=i; a[i][3]=x;
                        ~~~~~~^
/in/foo.cc:39:21: warning: array subscript is above array bounds [-Warray-bounds]
             a[a[x][3]][2]=a[x][2];
               ~~~~~~^
/in/foo.cc:40:33: warning: array subscript is above array bounds [-Warray-bounds]
             a[a[x][2]][3]=a[x][3];
                           ~~~~~~^
/in/foo.cc:40:25: warning: array subscript is above array bounds [-Warray-bounds]
             a[a[x][2]][3]=a[x][3];
             ~~~~~~~~~~~~^
/in/foo.cc:42:30: warning: array subscript is above array bounds [-Warray-bounds]
             if(x==j) j=a[x][3];
                        ~~~~~~^