UVA - 10305 Ordering Tasks（拓撲排序）

標籤：eps   stack   lib   ack   map   const   iostream   task   while   

題意：給定優先關係進行拓撲排序。

分析：將入度為0的點加入優先隊列，並將與之相連的點入度減1，若又有度數為0的點，繼續加入優先隊列，依次類推。

#pragma comment(linker, "/STACK:102400000, 102400000")#include<cstdio>#include<cstring>#include<cstdlib>#include<cctype>#include<cmath>#include<iostream>#include<sstream>#include<iterator>#include<algorithm>#include<string>#include<vector>#include<set>#include<map>#include<stack>#include<deque>#include<queue>#include<list>#define Min(a, b) ((a < b) ? a : b)#define Max(a, b) ((a < b) ? b : a)typedef long long ll;typedef unsigned long long llu;const int INT_INF = 0x3f3f3f3f;const int INT_M_INF = 0x7f7f7f7f;const ll LL_INF = 0x3f3f3f3f3f3f3f3f;const ll LL_M_INF = 0x7f7f7f7f7f7f7f7f;const int dr[] = {0, 0, -1, 1, -1, -1, 1, 1};const int dc[] = {-1, 1, 0, 0, -1, 1, -1, 1};const int MOD = 1e9 + 7;const double pi = acos(-1.0);const double eps = 1e-8;const int MAXN = 100 + 10;const int MAXT = 10000 + 10;using namespace std;int in[MAXN];vector<int> a[MAXN];vector<int> ans;priority_queue<int, vector<int>, greater<int> > q;int main(){    int n, m;    while(scanf("%d%d", &n, &m) == 2){        if(!n && !m) return 0;        memset(in, 0, sizeof in);        ans.clear();        for(int i = 0; i < MAXN; ++i) a[i].clear();        while(m--){            int x, y;            scanf("%d%d", &x, &y);            a[x].push_back(y);            ++in[y];        }        for(int i = 1; i <= n; ++i){            if(in[i] == 0){                q.push(i);            }        }        while(!q.empty()){            int t = q.top();            q.pop();            ans.push_back(t);            int len = a[t].size();            for(int i = 0; i < len; ++i){                if(--in[a[t][i]] == 0){                    q.push(a[t][i]);                }            }        }        int len = ans.size();        for(int i = 0; i < len; ++i){            if(i) printf(" ");            printf("%d", ans[i]);        }        printf("\n");    }    return 0;}

 

UVA - 10305 Ordering Tasks（拓撲排序）