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2018 Multi-University Training Contest 4 Problem L. Graph Theory Homework 【YY】

时间:2019-01-28 17:44:30      阅读:175      评论:0      收藏:0      [点我收藏+]

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传送门:http://acm.hdu.edu.cn/showproblem.php?pid=6343

Problem L. Graph Theory Homework

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 1536    Accepted Submission(s): 830


Problem Description
There is a complete graph containing n vertices, the weight of the i-th vertex is wi.
The length of edge between vertex i and j (ij) is ?|wi?wj|???????√?.
Calculate the length of the shortest path from 1 to n.
 

 

Input
The first line of the input contains an integer T (1T10) denoting the number of test cases.
Each test case starts with an integer n (1n105) denoting the number of vertices in the graph.
The second line contains n integers, the i-th integer denotes wi (1wi105).
 

 

Output
For each test case, print an integer denoting the length of the shortest path from 1 to n.
 

 

Sample Input
1
3
1 3 5
 

 

Sample Output
2
 

 

Source
 

 

题意概括:

给出每个点的权值,点与点之间的距离等于 √| wi-wj |  ,求起点到终点的最短距离。

 

解题思路:

一道伪装成图论的水题。

最短距离就是两点距离,因为如果中间放入其他点来进行更新路径是不会获得更短的路径的。

因为 √a + √b  > √(a+b) ;

AC code:

技术分享图片
 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<iostream>
 4 #include<cstring>
 5 #include<vector>
 6 #include<queue>
 7 #include<cmath>
 8 #include<set>
 9 #define INF 0x3f3f3f3f
10 #define LL long long
11 using namespace std;
12 int N;
13 
14 int myabs(int x)
15 {
16     if(x < 0) return -x;
17     return x;
18 }
19 
20 int main()
21 {
22     int w, st, ed;
23     int T_case;
24     scanf("%d", &T_case);
25     while(T_case--){
26         scanf("%d", &N);
27         for(int i = 1; i <= N; i++){
28             scanf("%d", &w);
29             if(i == 1) st = w;
30             if(i == N) ed = w;
31         }
32         int ans = sqrt(myabs(st-ed));
33         printf("%d\n", ans);
34     }
35     return 0;
36 }
View Code

 

2018 Multi-University Training Contest 4 Problem L. Graph Theory Homework 【YY】

标签:mit   script   int   col   mod   tween   color   case   cal   

原文地址:https://www.cnblogs.com/ymzjj/p/10330782.html

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