假设直线上有N个测站。它们各自具有相同的辐射功率的非负功率。每个站点可以通过以下方式增加其相邻站点的辐射功率。
假设具有辐射功率R的第i个站点,将第(i – 1)个站点的辐射功率增加R-1,第(i-2)个站点的辐射功率增加R-2,并将第(i + 1)个站点的辐射功率增加R-1的辐射功率,R-2的第(i + 2)站的辐射功率。等等。因此,例如,如果数组的值类似于Arr = [1、2、3],则输出将为3、4、4。新辐射将为[1 +(2-1 –)+(3-2), 2 +(1 – 1)+(3-1),3 +(2 – 1)] = [3,4,4]
这个想法很简单。对于每个站,如上 ,直到有效辐射变为负时,i都会增加相邻站的辐射。
#include <iostream> using namespace std; class pump { public: int petrol; int distance; }; int findStartIndex(pump pumpQueue[], int n) { int start_point = 0; int end_point = 1; int curr_petrol = pumpQueue[start_point].petrol - pumpQueue[start_point].distance; while (end_point != start_point || curr_petrol < 0) { while (curr_petrol < 0 && start_point != end_point) { curr_petrol -= pumpQueue[start_point].petrol - pumpQueue[start_point].distance; start_point = (start_point + 1) % n; if (start_point == 0) return -1; } curr_petrol += pumpQueue[end_point].petrol - pumpQueue[end_point].distance; end_point = (end_point + 1) % n; } return start_point; } int main() { pump PumpArray[] = {{4, 6}, {6, 5}, {7, 3}, {4, 5}}; int n = sizeof(PumpArray)/sizeof(PumpArray[0]); int start = findStartIndex(PumpArray, n); if(start == -1) cout<<"No solution"; else cout<<"Index of first petrol pump : "<<start; }
输出结果
Index of first petrol pump : 1