题目:https://blog.csdn.net/yao1373446012/article/details/52131283?utm_source=blogxgwz0
AC代码:
#include<bits/stdc++.h>
using namespace std;
struct Edg//边
{
int u, v;//顶点
char op;//运算符
}edg[10005];
vector<int>Mp[10005];//Mp数组存贮邻接表
int n, m, sum, In[10005], Father[10005];//In数组表示入度,Father[i]表示顶点i所在集合的根节点
int FindFather(int x)//查找根节点
{
return Father[x] == x ? x : FindFather(Father[x]);
}
bool Umerge(int x, int y)//合并集合
{
x = FindFather(x);
y = FindFather(y);
if (x == y)
return false;
else
{
Father[y] = x;
return true;
}
}
void init()//初始化
{
for (int i = 0; i<n; i++) Father[i] = i;
//重点注意 :遍历到N :不然,数据 3 3 1 > 2 1 =4 2 = 4 输出为错误答案OK。
memset(Mp, 0, sizeof(Mp));
memset(In, 0, sizeof(In));
}
void top_sort()//queue实现拓扑排序
{
queue<int>s;
int flag = 0;
for (int i = 0; i<n; i++)
{
if (In[i] == 0 && Father[i] == i)
s.push(i);
}
while (!s.empty())
{
if (s.size()>1)//即使发现信息不完整也要继续运行下去,因为如果信息同时不完整和冲突都是CONFLICT
flag = 1;
int pos = s.front();
s.pop(), sum--;
for (int i = 0; i<Mp[pos].size(); i++)
{
In[Mp[pos][i]]--;
if (In[Mp[pos][i]] == 0)
s.push(Mp[pos][i]);
}
}
if (sum>0) printf("CONFLICT\n");
else if (flag) printf("UNCERTAIN\n");
else printf("OK\n");
}
int main()
{
while (cin >> n >> m)
{
sum = n;
init();
for (int i = 0; i<m; i++)
{
cin >> edg[i].u >> edg[i].op >> edg[i].v;
if (edg[i].op == '=')
{
if (Umerge(edg[i].u, edg[i].v))
sum--;
}
}
for (int i = 0; i<m; i++)
{
if (edg[i].op == '=')
continue;
int x = FindFather(edg[i].u);
int y = FindFather(edg[i].v);
if (edg[i].op == '>')
{
Mp[x].push_back(y);
In[y]++;
}
else
{
Mp[y].push_back(x);
In[x]++;
}
}
top_sort();
}
}