Are macros difficult to debug

That was the way I used to build a centroid tree (a tree that connects all the adjacent centroids during centroid decomposition, used in 342E - Xenia and Tree):

That

ll n, ctroot, ctp[MAXN];
vector<ll> e[MAXN], ct[MAXN];
namespace centree {
	ll sz[MAXN], mxs[MAXN];
	bool vis[MAXN];
	void clear(ll x, ll pr) {
		sz[x] = mxs[x] = 0, mxs[0] = inf;
		for (ll i : e[x]) {
			if (i == pr || vis[i]) {
				continue;
			}
			clear(i, x);
		}
	}
	void setsz(ll x, ll pr) {
		sz[x] = 1;
		for (ll i : e[x]) {
			if (i == pr || vis[i]) {
				continue;
			}
			setsz(i, x);
			sz[x] += sz[i];
			mxs[x] = max(mxs[x], sz[i]);
		}
	}
	void fndct(ll x, ll pr, ll crt, ll &ret) {
		mxs[x] = max(mxs[x], sz[crt] - sz[x]);
		if (mxs[ret] > mxs[x]) {
			ret = x;
		}
		for (ll i : e[x]) {
			if (i == pr || vis[i]) {
				continue;
			}
			fndct(i, x, crt, ret);
		}
	}
	void bdct(ll x, ll pr) {
		ll cur = 0;
		clear(x, pr), setsz(x, pr), fndct(x, pr, x, cur);
		if (pr) {
			ct[pr].empb(cur);
			ctp[cur] = pr;
		} else {
			ctroot = cur;
		}
		vis[cur] = 1;
		for (ll i : e[cur]) {
			if (i == pr || vis[i]) {
				continue;
			}
			bdct(i, cur);
		}
	}
}

Then I found there were too many for (ll i : e[x]) if (i == pr || vis[i]) continue;s, so I used a macro to do shorten them:

them

ll n, ctroot, ctp[MAXN];
vector<ll> e[MAXN], ct[MAXN];
namespace centree {
	#define tra(x) for (ll i : e[x]) if (i != pr && !vis[i])
	ll sz[MAXN], mxs[MAXN];
	bool vis[MAXN];
	void clear(ll x, ll pr) {
		sz[x] = mxs[x] = 0, mxs[0] = inf;
		tra(x) {
			clear(i, x);
		}
	}
	void setsz(ll x, ll pr) {
		sz[x] = 1;
		tra(x) {
			setsz(i, x);
			sz[x] += sz[i];
			mxs[x] = max(mxs[x], sz[i]);
		}
	}
	void fndct(ll x, ll pr, ll crt, ll &ret) {
		mxs[x] = max(mxs[x], sz[crt] - sz[x]);
		if (mxs[ret] > mxs[x]) {
			ret = x;
		}
		tra(x) {
			fndct(i, x, crt, ret);
		}
	}
	void bdct(ll x, ll pr) {
		ll cur = 0;
		clear(x, pr), setsz(x, pr), fndct(x, pr, x, cur);
		if (pr) {
			ct[pr].empb(cur);
			ctp[cur] = pr;
		} else {
			ctroot = cur;
		}
		vis[cur] = 1;
		tra(cur) {
			bdct(i, cur);
		}
	}
	#undef tra
}

This reduces my code for about 150 bytes. But what I'm worrying now is: will macros increase the difficulty to debug my code, especially in some on-site contests, where templates are not allowed?

I also used #define mid ((lx+rx)>>1) #define l(x) ((x)<<1) #define r(X) (l(x)|1) in segment tree for months btw