View Compilation Error

0_0_21157878_28730.cpp: In function 'int dg(int, int, int)':
0_0_21157878_28730.cpp:19:11: error: expected primary-expression before 'if'
     while(if(a[i-1][p]==*))
           ^
0_0_21157878_28730.cpp:19:11: error: expected ')' before 'if'
0_0_21157878_28730.cpp:19:26: error: expected primary-expression before ')' token
     while(if(a[i-1][p]==*))
                          ^
0_0_21157878_28730.cpp:19:27: error: expected primary-expression before ')' token
     while(if(a[i-1][p]==*))
                           ^