POJ-1511-Invitation cards

POJ-1511-Invitation cards

Http://poj.org/problem? Id = 1511

The meaning of this question is to give some edges, find the sum of the distance between the first point and other points + the minimum value of the sum of the distance between the other points and the first point, and find the shortest distance between the two single source points, find the minimum distance between the first vertex and other points for the first time, and reverse all the directed edges for the second time, the minimum distance between the first vertex and other vertices is the minimum distance between the other vertices and the first vertex in the source image.

# Include <iostream> # include <cstdio> # include <cstring> # include <queue> using namespace STD; # define n 1000010 # define Max 0x7fffffint head [N], nextt [N], key [N], num [N], visit [N]; int t ;__ int64 dis [N]; int nodenum, edgenum; struct cam // directed edge {int St, Ed; int V;} edge [N]; void add (INT St, int ed, int V) {key [T] = V; nextt [T] = head [st]; // The Last edge num [T] = ed starting from U; head [st] = T ++; // an edge closest to the start point of St} void Init () {T = 0; memset (Head,-1, sizeof (H EAD); For (INT I = 1; I <= nodenum; I ++) dis [I] = max ;__ int64 spfa (INT start) {_ int64 Total = 0; int temp; queue <int> q; while (! Q. empty () Q. pop (); memset (visit, 0, sizeof (visit); DIS [start] = 0; visit [start] = 1; q. push (start); While (! Q. Empty () {temp = Q. Front (); q. Pop (); visit [temp] = 0; For (INT I = head [temp]; I! =-1; I = nextt [I]) {If (DIS [num [I]> dis [temp] + key [I]) {dis [num [I] = dis [temp] + key [I]; If (! Visit [num [I]) {q. push (Num [I]); visit [num [I] = 1 ;}}}for (INT I = 1; I <= nodenum; I ++) total + = dis [I]; return total;} int main () {int top, CAS ;__ int64 ans; scanf ("% d", & CAS ); while (CAS --) {Top = ans = 0; scanf ("% d", & nodenum, & edgenum); Init (); For (INT I = 0; I <edgenum; I ++) {scanf ("% d", & edge [Top]. st, & edge [Top]. ed, & edge [Top]. v); add (edge [Top]. st, edge [Top]. ed, edge [Top]. v); top ++;} ans + = spfa (1); Init (); For (INT I = 0; I <top; I ++) add (edge [I]. ed, edge [I]. st, edge [I]. v); ans + = spfa (1); printf ("% i64d \ n", ANS);} return 0 ;}