CF - 1131 D Gourmet choice

题目传送门

先把 = 的人用并查集合并在一起。

然后 < > 的建边， 跑一遍 toposort 之后就好了。

入度为0点的值肯定为1， 然后就是因为这个是按照时间线走过来的，所以一个点的最小值，就是在入队的那一刻确定的， 即入度为0的时候，值就是现在的值+1。

注意就是不要同一个点入队多次。

代码：

/*
code by: zstu wxk
time: 2019/02/24
*/
#include<bits/stdc++.h>
using namespace std;
#define Fopen freopen("_in.txt","r",stdin); freopen("_out.txt","w",stdout);
#define LL long long
#define ULL unsigned LL
#define fi first
#define se second
#define pb push_back
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define lch(x) tr[x].son[0]
#define rch(x) tr[x].son[1]
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
typedef pair<int,int> pll;
const int inf = 0x3f3f3f3f;
const int _inf = 0xc0c0c0c0;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const LL _INF = 0xc0c0c0c0c0c0c0c0;
const LL mod =  (int)1e9+;
const int N = 2e3 + ;
int pre[N];
int ind[N];
int val[N];
int n, m;
char s[N][N];
vector<int> vc[N];
int Find(int x){
    if(x == pre[x]) return x;
    return pre[x] = Find(pre[x]);
}
queue<int> q;
void toposort(){
    for(int i = ; i <= n+m; ++i){
//        cout << i << ' ' << ind[i] << endl;
        if(i == Find(i) && ind[i] == ) {
            q.push(i), val[i] = ;
//            cout  << i << endl;
        }
    }
    while(!q.empty()){
        int x = q.front();
        q.pop();
        for(int v : vc[x]){
            ind[v]--;
            if(ind[v] == ){
                val[v] = val[x] + ;
                q.push(v);

            }
        }
    }
}
void Ac(){
    for(int i = ; i <= n + m; ++i) pre[i] = i, ind[i] = ;
    for(int i = ; i <= n; ++i){
        scanf("%s", s[i]+);
        for(int j = ; j <= m; ++j){
            if(s[i][j] == '='){
                int u = Find(i), v = Find(n+j);
                if(u == v) continue;
                pre[u] = v;
            }
        }
    }
    for(int i = ; i <= n; ++i){
        for(int j = ; j <= m; ++j){
            if(s[i][j] == '=' ) continue;
            int u = Find(i), v = Find(n+j);
            if(s[i][j] == '<'){
                vc[u].pb(v);
                ind[v]++;
            }
            else {
                vc[v].pb(u);
                ind[u]++;
            }
        }
    }
    toposort();
    for(int i = ; i <= n+m; ++i){
        if(!val[Find(i)]){
            puts("No");
            return ;
        }
    }
    puts("Yes");
    for(int i = ; i <= n; ++i){
        printf("%d%c", val[Find(i)]," \n"[i==n]);
    }
    for(int i = ; i <= m; ++i){
        printf("%d%c", val[Find(i+n)], " \n"[i==m]);
    }
}
int main(){
    while(~scanf("%d%d", &n, &m)){
        Ac();
    }
    return ;
}