标签:style blog class code java tar
裸差分约束。
//#pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<iostream> #include<sstream> #include<cmath> #include<climits> #include<string> #include<map> #include<queue> #include<vector> #include<stack> #include<set> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> pii; #define pb(a) push(a) #define INF 0x1f1f1f1f #define lson idx<<1,l,mid #define rson idx<<1|1,mid+1,r #define PI 3.1415926535898 template<class T> T min(const T& a,const T& b,const T& c) { return min(min(a,b),min(a,c)); } template<class T> T max(const T& a,const T& b,const T& c) { return max(max(a,b),max(a,c)); } void debug() { #ifdef ONLINE_JUDGE #else freopen("data.in","r",stdin); // freopen("d:\\out1.txt","w",stdout); #endif } int getch() { int ch; while((ch=getchar())!=EOF) { if(ch!=‘ ‘&&ch!=‘\n‘)return ch; } return EOF; } struct Edge { int from, to, dist; }; const int maxn = 1111; int n; vector<int> g[maxn]; vector<Edge> edge; void Init() { for(int i = 1; i <= n; i++) g[i].clear(); edge.clear(); } void AddEdge(int u, int v, int w) { edge.push_back((Edge){u, v, w}); g[u].push_back(edge.size() - 1); } int inq[maxn]; int cnt[maxn]; int d[maxn]; bool SPFA() { queue<int> q; for(int i=1; i<=n; i++) { inq[i] = true; cnt[i] = 0; d[i] = 0; q.push(i); } while(!q.empty()) { int u = q.front(); q.pop(); inq[u] = false; for(int i=0; i < g[u].size(); i++) { //cout<<g[u][i]<<endl; Edge &e = edge[ g[u][i] ]; //cout<<" "<<e.from<<" "<<e.to<<" "<<e.dist<<endl; if(d[e.to] < d[u] + e.dist) { d[e.to] = d[u] + e.dist; inq[e.to] = true; if(++cnt[e.to] > n) return 0; q.push(e.to); } } } return 1; } int main() { debug(); int m; while(scanf("%d%d", &n, &m) != EOF) { Init(); for(int i = 1; i <= m; i++) { char op = getch(); if(op == ‘P‘) { int u,v,x; scanf("%d%d%d", &u, &v, &x); AddEdge(u,v,x); AddEdge(v,u,-x); }else { int u,v; scanf("%d%d", &u, &v); AddEdge(v,u,1); } } //cout<<edge.size()<<endl; // for(int i=0; i<=n; i++) // cout<<g[i].size()<<endl; int ans = SPFA(); printf("%s\n", ans?"Reliable":"Unreliable"); } return 0; }
POJ 2983 Is the Information Reliable? 差分约束,布布扣,bubuko.com
POJ 2983 Is the Information Reliable? 差分约束
标签:style blog class code java tar
原文地址:http://www.cnblogs.com/BMan/p/3703505.html