The task is really simple: given N exits on a highway which forms a simple cycle, you are supposed to tell the shortest distance between any pair of exits.
Input Specification:
Each input file contains one test case. For each case, the first line contains an integer N (in [3, 105]), followed by N integer distances D1 D2 ... DN, where Di is the distance between the i-th and the (i+1)-st exits, and DN is between the N-th and the 1st exits. All the numbers in a line are separated by a space. The second line gives a positive integer M (<=104), with M lines follow, each contains a pair of exit numbers, provided that the exits are numbered from 1 to N. It is guaranteed that the total round trip distance is no more than 107.
Output Specification:
For each test case, print your results in M lines, each contains the shortest distance between the corresponding given pair of exits.
Sample Input:5 1 2 4 14 9 3 1 3 2 5 4 1Sample Output:
3 10 7
http://pat.zju.edu.cn/contests/pat-a-practise/1046
题意
给定在圆环上的几个点的相对位置,要求计算不同点之间的距离。
分析
简单模拟。
#include <iostream> #define MAX 100000 int g_Dis[MAX]; int g_Sum[MAX+1]; int Min(int a,int b) { if(a>b) return b; else return a; } int main () { int n; while(scanf("%d",&n)!=EOF) { int total=0; g_Sum[0]=0; for(int i=0;i<n;++i) { scanf("%d",&g_Dis[i]); total+=g_Dis[i]; if(i==0) g_Sum[i+1]=g_Dis[i]; else g_Sum[i+1]=g_Dis[i]+g_Sum[i]; } int m; scanf("%d",&m); while(m--) { int a,b; scanf("%d%d",&a,&b); if(a>b) { int tmp=a; a=b; b=tmp; } int ans = g_Sum[b-1]-g_Sum[a-1]; ans=Min(ans,total-ans); printf("%d",ans); } } return 0; }