/in/foo.cc: In function 'int main()':
/in/foo.cc:20:12: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
          if(k*c[i]<=j) 
            ^
/in/foo.cc:30:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
         for(int j=m-1;j>0;j--)
         ^~~
/in/foo.cc:32:11: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
           cout<<f[n][k]<<endl;
           ^~~~
/in/foo.cc:39:21: warning: operation on 'l' may be undefined [-Wsequence-point]
            a[--l]=d[--l][k];
                     ^~~