Submission #1771899

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Source Code Expand

// XOR Replace
// * frank_c1
// * 2017 / 11 / 14

#include <bits/stdc++.h>
using namespace std;

const int maxn = (int)(2e5) + 5;
int a[maxn], b[maxn], c[maxn], fa[maxn], vi[maxn], T[maxn];
int n, tot;

inline int hs(int x) {
	return lower_bound(T + 1, T + tot + 1, x) - T;
}

int Find(int x) {
	return fa[x] == x ? x : fa[x] = Find(fa[x]);
}

int main() {
	scanf("%d", &n); ++n;
	for (int i = 1; i < n; ++i) scanf("%d", &a[i]), a[n] ^= a[i];
	for (int i = 1; i < n; ++i) scanf("%d", &b[i]), b[n] ^= b[i];
	for (int i = 1; i <= n; ++i) T[++tot] = a[i], T[++tot] = b[i];
	sort(T + 1, T + tot + 1);
	tot = unique(T + 1, T + tot + 1) - T - 1;
	for (int i = 1; i <= n; ++i) ++c[a[i] = hs(a[i])], --c[b[i] = hs(b[i])];
	for (int i = 1; i <= tot; ++i) if (c[i]) return printf("-1\n"), 0;
	for (int i = 1; i <= tot; ++i) fa[i] = i;
	int ret = 0, sgn = 0;
	for (int i = 1; i <= n; ++i) {
		if (a[i] != b[i]) {
			if (!vi[a[i]]) vi[a[i]] = 1, sgn = -1;
			if (!vi[b[i]]) vi[b[i]] = 1, sgn = -1;
			if (i < n) fa[Find(a[i])] = Find(b[i]), ++ret;
		}
	}
	for (int i = 1; i <= tot; ++i) if (vi[i] && Find(i) == i) ++ret;
	return printf("%d\n", ret + sgn), 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:21:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n); ++n;
                 ^
./Main.cpp:22:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 1; i < n; ++i) scanf("%d", &a[i]), a[n] ^= a[i];
                                                              ^
./Main.cpp:23:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 1; i < n; ++i) scanf("%d", &b[i]), b[n] ^= b[i];
                                                              ^

Judge Result