53 lines
1.3 KiB
C++
53 lines
1.3 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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const int N = 50005;
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int p[N];
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int d[N]; // 0 ： 同类 1：吃 2：被吃
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// 分析：https://blog.csdn.net/yjr3426619/article/details/82315133
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// A吃B B吃C ==> A被C吃 Relation(a,c) = Relation(a,b)+Relation(b,c)
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// A被B吃 B被C吃 ==> A吃C Relation(a,c) = (Relation(a,b)+Relation(b,c))%3
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int find(int x) {
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if (x != p[x]) {
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int t = p[x];
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p[x] = find(p[x]);
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d[x] = (d[x] + d[t]) % 3;
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}
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return p[x];
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}
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int main() {
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//输入+输出重定向
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freopen("../AcWing/N5/poj-1182.txt", "r", stdin);
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int n, k;
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cin >> n >> k;
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int ans = 0;
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for (int i = 1; i <= n; i++) {
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p[i] = i;
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}
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while (k--) {
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int relation, x, y;
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scanf("%d%d%d", &relation, &x, &y);
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if (x > n || y > n || (relation == 2 && x == y)) {
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ans++;
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} else {
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int fx = find(x);
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int fy = find(y);
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if (fx == fy) {
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if ((relation - 1) != ((d[x] - d[y] + 3) % 3))
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ans++;
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} else {
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p[fx] = fy;
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d[fx] = (-d[x] + relation - 1 + d[y]) % 3;
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}
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}
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}
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cout << ans;
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//关闭文件
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fclose(stdin);
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return 0;
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} |