1549: Navigition Problem
Submit Page Summary Time Limit: 1 Sec Memory Limit: 256 Mb Submitted: 400 Solved: 122
Description
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation. (From Wikipedia)
Recently, slowalker encountered a problem in the project development of Navigition APP. In order to provide users with accurate navigation service , the Navigation APP should re-initiate geographic location after the user walked DIST meters. Well, here comes the problem. Given the Road Information which could be abstracted as N segments in two-dimensional space and the distance DIST, your task is to calculate all the postion where the Navigition APP should re-initiate geographic location.
Input
The input file contains multiple test cases.
For each test case,the first line contains an interger N and a real number DIST. The following N+1 lines describe the road information.
You should proceed to the end of file.
Hint:
1 <= N <= 1000
0 < DIST < 10,000
Output
For each the case, your program will output all the positions where the Navigition APP should re-initiate geographic location. Output “No Such Points.” if there is no such postion.
Sample Input
2 0.50 0.00 0.00 1.00 0.00 1.00 1.00
Sample Output
0.50,0.00 1.00,0.00 1.00,0.50 1.00,1.00
题目意思:
给你很多点,将这些点连成线段,起点和终点不相连
从起点出发,沿着这些折线走,每一次走d距离
问你每走d距离达到的所有点的坐标
(包括起点和终点)
分析:
就是几何计算+模拟,细节多,每沿着折线走d距离,就是输出一下到达该点的坐标
总长度不足d
就按照题目输出字符串
下一步走d距离超过了终点的话
最后只要输出终点
不用输出超出终点的点
#include<cstdio> #include<string> #include<cstdlib> #include<cmath> #include<iostream> #include<cstring> #include<set> #include<queue> #include<algorithm> #include<vector> #include<map> #include<cctype> #include<stack> #include<sstream> #include<list> #include<assert.h> #include<bitset> #include<numeric> using namespace std; typedef long long LL; #define max_v 1005 struct node { double x,y; }p[max_v]; double len[max_v]; double dis(node a,node b) { return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)); } double sum[max_v]; int main() { int n; double d; while(~scanf("%d %lf",&n,&d)) { double c=0; sum[0]=0; for(int i=1;i<=n+1;i++) { scanf("%lf %lf",&p[i].x,&p[i].y); if(i>1) { len[i-1]=dis(p[i],p[i-1]); c+=len[i-1]; sum[i-1]=sum[i-2]+len[i-1]; } } if(c<d) { printf("No Such Points.\n"); continue; } double now=0,k,x,y; for(int i=1;i<=n;) { if(now+d<=sum[i]) { double L=now+d-sum[i-1]; double x1=p[i].x; double y1=p[i].y; double x2=p[i+1].x; double y2=p[i+1].y; if(x1!=x2) { k=(y1-y2)/(x1-x2); if(x2<x1) { x=x1-sqrt((L*L)/(k*k+1)); y=k*(x-x1)+y1; }else { x=x1+sqrt((L*L)/(k*k+1)); y=k*(x-x1)+y1; } }else { x=x1; if(y2<y1) y=y1-L; else y=y1+L; } printf("%.2lf,%.2lf\n",x,y); now=now+d; }else { i++; } } } return 0; } /* 题目意思: 给你很多点,将这些点连成线段,起点和终点不相连 从起点出发,沿着这些折线走,每一次走d距离 问你每走d距离达到的所有点的坐标 (包括起点和终点) 分析: 就是几何计算+模拟,细节多,每沿着折线走d距离,就是输出一下到达该点的坐标 总长度不足d 就按照题目输出字符串 下一步走d距离超过了终点的话 最后只要输出终点 不用输出超出终点的点 */
原文地址:https://www.cnblogs.com/yinbiao/p/9498593.html