编辑
2025-08-30
XCPC
00
#include <bits/stdc++.h> using namespace std; #define int long long const int M = 1e5 + 5; int a[M], cnt = 1, vis[M]; int n, m, s, t; int head[M], pre[M], mf[M], dis[M]; struct dian { int to, c, w, ne; } f[M]; int cost, flow; void add(int x, int y, int c, int w) { f[++cnt].to = y; f[cnt].c = c; f[cnt].w = w; f[cnt].ne = head[x]; head[x] = cnt; f[++cnt].to = x; f[cnt].c = 0; f[cnt].w = -w; f[cnt].ne = head[y]; head[y] = cnt; } int bfs() { for (int i = 1; i <= n; ++i) mf[i] = 0; mf[s] = 1e18; for (int i = 1; i <= n; ++i) dis[i] = 1e18; dis[s] = 0; queue<int> p; p.push(s); vis[s] = 1; while (!p.empty()) { int t = p.front(); p.pop(); vis[t] = 0; for (int i = head[t]; i; i = f[i].ne) { int to = f[i].to, c = f[i].c, w = f[i].w; if (c && dis[t] + w < dis[to]) { dis[to] = dis[t] + w; mf[to] = min(mf[t], c); pre[to] = i; if (!vis[to]) vis[to] = 1, p.push(to); } } } return mf[t] > 0; } void ek() { while (bfs()) { int now = t; while (now != s) { int q = pre[now]; f[q].c -= mf[t]; f[q ^ 1].c += mf[t]; now = f[q ^ 1].to; } flow += mf[t]; cost += mf[t] * dis[t]; } } void solve() { cin >> n >> m >> s >> t; cnt = 1; while (m--) { int a, b, c, d; cin >> a >> b >> c >> d; add(a, b, c, d); } ek(); cout << flow << ' ' << cost; for (int i = 1; i <= n; ++i) { vis[i] = head[i] = mf[i] = pre[i] = dis[i] = 0; } } signed main() { ios::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL); int T = 1; // cin>>T; while (T--) solve(); return 0; }
编辑
2025-08-30
XCPC
00
#include <bits/stdc++.h> using namespace std; #define int long long const long long inf=1e18; const int M=1e6+5; int n,m,s,t; int dis[M],now[M],head[M]; int cnt=1; struct node { int to,net,w; } e[M]; inline void add(int u,int v,int w) { e[++cnt].to=v; e[cnt].w=w; e[cnt].net=head[u]; head[u]=cnt; e[++cnt].to=u; e[cnt].w=0; e[cnt].net=head[v]; head[v]=cnt; } inline int bfs() { //在惨量网络中构造分层图 for(int i=1;i<=n;i++) dis[i]=inf; queue<int> q; q.push(s); dis[s]=0; now[s]=head[s]; while(!q.empty()) { int x=q.front(); q.pop(); for(int i=head[x];i;i=e[i].net) { int v=e[i].to; if(e[i].w>0&&dis[v]==inf) { q.push(v); now[v]=head[v]; dis[v]=dis[x]+1; if(v==t) return 1; } } } return 0; } inline int dfs(int x,long long sum) { //sum是整条增广路对最大流的贡献 if(x==t) return sum; long long k,res=0; //k是当前最小的剩余容量 for(int i=now[x];i&&sum;i=e[i].net) { now[x]=i; //当前弧优化 int v=e[i].to; if(e[i].w>0&&(dis[v]==dis[x]+1)) { k=dfs(v,min(sum,e[i].w)); if(k==0) dis[v]=inf; //剪枝,去掉增广完毕的点 e[i].w-=k; e[i^1].w+=k; res+=k; //res表示经过该点的所有流量和(相当于流出的总量) sum-=k; //sum表示经过该点的剩余流量 } } return res; } void solve() { cin>>n>>m>>s>>t; cnt=1; for(int i=1;i<=m;i++) { int u,v,w; cin>>u>>v>>w; add(u,v,w); } int ans=0; while(bfs()) { ans+=dfs(s,inf); //流量守恒(流入=流出) } cout<<ans; for (int i=0;i<=cnt+n;++i) { dis[i]=now[i]=head[i]=0; } cnt=1; } signed main() { ios::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL); int t=1; // cin>>t; while(t--) solve(); return 0; }
编辑
2025-08-30
XCPC
00
#include <bits/stdc++.h> using namespace std; #define int long long const int M = 2e6 + 5; int vis[M], ans[M]; struct edge { int to, w; }; vector<edge> f[M]; void add(int x, int y, int l) { f[x].push_back({y, l}); } void dij(int s, int n) { priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> p; for (int i = 1; i <= n; i++) ans[i] = 1e18; ans[s] = 0; p.push({0, s}); while (!p.empty()) { auto [dis, id] = p.top(); p.pop(); if (vis[id]) continue; vis[id] = 1; for (auto [y, w] : f[id]) { if (w + ans[id] < ans[y]) { ans[y] = w + ans[id]; p.push({ans[y], y}); } } } for (int i = 1; i <= n; i++) cout << ans[i] << " "; for (int i = 1; i <= n; ++i) { f[i].clear(); vis[i] = 0; } } void solve() { int n, m, s, x, y, l; cin >> n >> m >> s; for (int i = 1; i <= m; ++i) { cin >> x >> y >> l; add(x, y, l); } dij(s, n); } signed main() { ios::sync_with_stdio(false), cin.tie(0), cout.tie(0); int t = 1; // cin>>t; while (t--) solve(); return 0; }
编辑
2025-08-05
java炒饭
00

编辑
2025-08-03
XCPC
00

行数不知道

string line; while (getline(cin, line)) { stringstream ss(line); string s; while (ss >> s) { cout << s << endl; } }