Update dsu var (#166)

* change

* fix

Author: lrvideckis

library/data_structures/dsu/dsu.hpp

@@ -1,13 +1,13 @@
 #pragma once
 // NOLINTNEXTLINE(readability-identifier-naming)
 struct DSU {
-  vi e;
-  DSU(int n): e(n, -1) {}
-  int size(int x) { return -e[go(x)]; }
-  int go(int x) { return e[x] < 0 ? x : e[x] = go(e[x]); }
+  vi p;
+  DSU(int n): p(n, -1) {}
+  int size(int x) { return -p[go(x)]; }
+  int go(int x) { return p[x] < 0 ? x : p[x] = go(p[x]); }
   bool join(int a, int b) {
     if ((a = go(a)) == (b = go(b))) return 0;
-    if (e[a] > e[b]) swap(a, b);
-    return e[a] += e[b], e[b] = a, 1;
+    if (p[a] > p[b]) swap(a, b);
+    return p[a] += p[b], p[b] = a, 1;
   }
 };

tests/library_checker_aizu_tests/graphs/offline_incremental_scc.test.cpp

@@ -27,7 +27,7 @@ int main() {
       auto [u, v] = eds[order[it]];
       u = dsu.go(u);
       v = dsu.go(v);
-      if (dsu.e[u] > dsu.e[v]) swap(u, v);
+      if (dsu.p[u] > dsu.p[v]) swap(u, v);
       if (u != v) {
         sum = (sum + 1LL * xs[u] * xs[v]) % mod;
         xs[u] = (xs[u] + xs[v]) % mod;