[Floyd + split point + second answer + network stream] poj 2391

# Include <map> # include <set> # include <list> # include <queue> # include <deque> # include <stack> # include <string> # include <cstdio> # include <math. h> # include <iomanip> # include <cstdlib> # include <limits. h> # include <string. h> # include <iostream> # include <fstream> # include <algorithm> using namespace STD; # define ll long # define PII pair <int, int> # define bug cout <"here !! "<Endl # define PI ACOs (-1.0) # define fre freopen (" input.txt "," r ", stdin) # define FF freopen (" output.txt "," W ", stdout) # define EPS 1e-8 # define min int_minconst ll max = (1ll <58); const int INF = (1 <29 ); # define n 410 # define M (N * n) int n, m; // n indicates the number of points. M indicates the number of edges. Int H [N]; int gap [N]; int P [N], ecnt; int source, sink; struct edge {int V; int next; int val;} e [m]; inline void Init () {memset (p,-1, sizeof (p); ecnt = 0;} // directed inline Vo Id insert1 (int from, int to, int Val) {e [ecnt]. V = to; E [ecnt]. val = val; E [ecnt]. next = P [from]; P [from] = ecnt ++; swap (from, to); e [ecnt]. V = to; E [ecnt]. val = 0; E [ecnt]. next = P [from]; P [from] = ecnt ++;} // undirected inline void insert2 (int from, int to, int Val) {e [ecnt]. V = to; E [ecnt]. val = val; E [ecnt]. next = P [from]; P [from] = ecnt ++; swap (from, to); e [ecnt]. V = to; E [ecnt]. val = val; E [ecnt]. next = P [from]; P [from] = ecnt ++;} inline in T DFS (INT POs, int cost) {If (Pos = sink) {return cost;} Int J, Minh = n-1, Lv = Cost, D; for (j = P [POS]; J! =-1; j = E [J]. next) {int v = E [J]. v, val = E [J]. val; If (Val> 0) {If (H [v] + 1 = H [POS]) {If (LV <E [J]. val) d = lv; else d = E [J]. val; D = DFS (v, d); e [J]. val-= D; E [J ^ 1]. val + = D; LV-= D; If (H [Source]> = N) return cost-lv; If (Lv = 0) break ;} if (H [v] <Minh) Minh = H [v] ;}} if (Lv = cost) {-- gap [H [POS]; if (gap [H [POS] = 0) H [Source] = N; H [POS] = Minh + 1; ++ gap [H [POS];} return cost-lv;} int SAP (INT St, int ed) {source = sT; sink = ed; Int ans = 0; memset (GAP, 0, sizeof (GAP); memset (H, 0, sizeof (h); Gap [st] = N; while (H [st] <n) {ans + = DFS (St, int_max);} return ans;} ll G [205] [205]; int flow; int X [205], Y [205]; void Floyd (int nn) {int I, j, k; For (k = 1; k <= nn; k ++) {for (I = 1; I <= nn; I ++) {If (G [I] [k] <max) for (j = 1; j <= nn; j ++) {If (G [k] [J] <max) if (G [I] [k] + G [k] [J] <G [I] [J]) {G [I] [J] = G [I] [k] + G [k] [J] ;}}} bool chk (LL mid, int NN) {int I, J; Init (); for (I = 1; I <= nn; I ++) {insert1 (I, I + NN, INF); insert1 (0, I, X [I]); insert1 (I + NN, n-1, Y [I]);} for (I = 1; I <nn; I ++) {for (j = I + 1; j <= nn; j ++) {If (G [I] [J] <= mid) {insert1 (I, J + NN, INF); insert1 (J, I + NN, INF) ;}}int ans = SAP (0, n-1); Return ans = flow ;} ll l, R, mid; void Gao (int nn) {L = 0; ll ans =-1; while (L <= r) {mid = (L + r)> 1; if (chk (MID, NN) {r = mid-1; ans = mid ;} else l = Mid + 1;} If (ANS =-1) puts ("- 1 "); else printf (" % i64d \ n ", ANS);} int main () {fre; while (scanf (" % d ", & N, & M )! =-1) {int I, j; for (I = 1; I <= N; I ++) {for (j = 1; j <= N; j ++) {G [I] [J] = max;} G [I] [I] = 0;} int nn = N; n = 2 * n + 2; flow = 0; r = 0; for (I = 1; I <= nn; I ++) {scanf ("% d", & X [I], & Y [I]); flow + = x [I];} while (M --) {int A, B; ll C; scanf ("% d % i64d", & A, & B, & C); If (G [a] [B]> C) {G [a] [B] = G [B] [a] = C; R + = C ;}} Floyd (NN); Gao (NN );} return 0 ;}