poj1703

简单并查集

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#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

#define maxn 100005

int n, m;
int f[maxn], father[maxn];

int getanc(int a)
{
if (a == father[a])
return a;
return father[a] = getanc(father[a]);
}

void merge(int a, int b)
{
father[getanc(a)] = getanc(b);
}

void differ(int a, int b)
{
if (f[a] == -1)
f[a] = b;
else
merge(f[a], b);
if (f[b] == -1)
f[b] = a;
else
merge(f[b], a);
}

void ask(int a, int b)
{
if (f[a] == -1 || f[b] == -1)
{
printf("Not sure yet.\n");
return;
}
if (getanc(a) == getanc(b))
{
printf("In the same gang.\n");
return;
}
if (getanc(a) == getanc(f[b]))
{
printf("In different gangs.\n");
return;
}
printf("Not sure yet.\n");
}

int main()
{
//freopen("t.txt", "r", stdin);
int t;
scanf("%d", &t);
while (t--)
{
memset(f, -1, sizeof(f));
scanf("%d%d", &n, &m);
getchar();
for (int i = 0; i < n; i++)
father[i] = i;
for (int i = 0; i < m; i++)
{
char ch;
int a, b;
scanf("%c%d%d", &ch, &a, &b);
a--;
b--;
getchar();
if (ch == 'D')
differ(a, b);
else
ask(a, b);
}
}
return 0;
}

转载于:https://www.cnblogs.com/rainydays/archive/2011/06/11/2078375.html