/in/foo.cc: In function 'int main()':
/in/foo.cc:25:11: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
           if(a[j].num<a[j+1].num)
           ^~
/in/foo.cc:26:30: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
               t.num=a[j].num;a[j].num=a[j+1].num;a[j+1].num=t.num;t.sum=a[j].sum;a[j].sum=a[j+1].sum;a[j+1].sum=t.sum;
                              ^
/in/foo.cc:26:60: warning: 't.main()::y::num' may be used uninitialized in this function [-Wmaybe-uninitialized]
               t.num=a[j].num;a[j].num=a[j+1].num;a[j+1].num=t.num;t.sum=a[j].sum;a[j].sum=a[j+1].sum;a[j+1].sum=t.sum;
                                                  ~~~~~~~~~~^~~~~~