1046. Shortest Distance (20)
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 D1D2... DN, where Diis the distance between the i-th and the (i+1)-st exits, and DNis 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 1
Sample Output:
3
10
7
思路：以dis[i]表示1號(hào)節(jié)點(diǎn)按順時(shí)間方向到達(dá)“i號(hào)節(jié)點(diǎn)順時(shí)鐘方向的下一個(gè)節(jié)點(diǎn)”的距離*(1<<i<<N)于是對(duì)每個(gè)查詢left---right，其結(jié)果就是dis(left, right)與sum - dis(left, right)中的最小值。
關(guān)鍵點(diǎn)
此題如果沒有經(jīng)過預(yù)處理dis數(shù)組(把dis數(shù)組做成一個(gè)累加數(shù)組)和sum的做法很容易超時(shí)
