题目描述 Bessie has moved to a small farm and sometimes enjoys returning to visit one of her best friends. She does not want to get to her old home too quickly, because she likes the scenery along the wa

题目大意： 求一个无向图的次短路。 Input I n p u t Input 4 41 2 1002 4 2002 3 2503 4 100 Output O u t p u t Output 450 思路： 这道题，正解是跑两遍 SPFA S P F A SPFA，一遍是从点 1 1 1，求出到达其他点的最短路径，记作dis1[i]dis1[i]dis1