【LeetCode 004】各种分类讨论

写不出来不肯睡觉系列。。。。。。

#include<stdio.h>
#include<iostream>
#include<vector>
using namespace std;

class Solution {
public:
	int upper(vector<int> a, int l, int r, int key){
		if(a.size() == 0) return -1;
		if (key <= a[l]) {
			while(key == a[l]) l++;
			return l;
		}
		int mid;
		while (l <= r) {
			mid = (l + r) >> 1;
			if (a[mid - 1] <= key && key <=a[mid]) return mid;
			if (a[mid - 1] >= key) {
				r = mid - 1;
			} else {
				l = mid + 1;
			}
		}
		return r + 1;
	}

    double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) {
        int minL = nums1.size();
		int maxL = nums2.size();
		vector<int> minN;
		vector<int> maxN;
		if (minL <= maxL) {
			minN = nums1;
			maxN = nums2;
		} else {
			minL = nums2.size();
			maxL = nums1.size();
			minN = nums2;
			maxN = nums1;
		}

		int oneDone = -1;
		if (minL == 0) {
			oneDone = 0;
		} else if(maxL == 0){
			oneDone = 1;
		}
		int curL = 0;
		int cen = (minL + maxL) / 2;
		//printf("%d\n", cen);
		int minP = 0;
		int maxP = 0;
		int index;
		int minMax = 0;
		while (curL < cen) {
			if(oneDone != -1) break;
			if(maxP + 1 < maxL && maxN[maxP] == maxN[maxP + 1]) {
				maxP++;
				curL++;
			}
			index = upper(minN, minP, minL - 1, maxN[maxP]);
		//	while(index < minL && maxN[maxP] == minN[index]) index++;
			curL += index - minP;
			minP = index;
			minMax = 0;
			//printf("cen = %d, curL = %d, minP = %d, maxP = %d, index = %d\n", cen, curL, minP, maxP, index);
			if (minP >= minL){
				oneDone = 0;
				break;
			}
			if (curL >= cen) break;

			if(minP + 1 < minL && minN[minP] == minN[minP + 1]) {
				minP++;
				curL++;
			}
			index = upper(maxN, maxP, maxL - 1, minN[minP]);
			//while(index < maxL && minN[minP] == maxN[index]) index++;
			curL += index - maxP;
			maxP = index;
			minMax = 1;
			//printf("cen = %d, curL = %d, minP = %d, maxP = %d, index = %d\n", cen, curL, minP, maxP, index);
			if (maxP >= maxL){
				oneDone = 1;
				break;
			}
			if (curL >= cen) break;
			//int haha;
			//scanf("%d",&haha);
		}
		double ans = 0;
		if (oneDone == 0) {
			if (curL > cen) {
				int indexR = index - (curL - cen);
				if ((minL + maxL) % 2 == 1) {
					ans = minN[indexR];
				} else {
					int indexL = indexR - 1;
					double cenR = minN[indexR];
					double cenL = minN[indexL];
					if (maxN[maxP] > minN[indexL]) {
						cenL = maxN[maxP];
					}
					ans = (cenR + cenL) / 2.0;
				}
			} else {
				int indexR = maxP + cen - curL;
				if ((minL + maxL) % 2 == 1) {
					ans = maxN[indexR];
				} else {
					int indexL = indexR - 1;
					if (indexL >= 0) {
						ans = (maxN[indexL] + maxN[indexR]) / 2.0;
					}

					if (minN[minL - 1] > maxN[indexL]) {
						ans = (minN[minL - 1] + maxN[indexR]) / 2.0;
					}
				}
			}
		} else if (oneDone == 1) {
			if (curL > cen) {
				int indexR = index - (curL - cen);
				if ((minL + maxL) % 2 == 1) {
					ans = maxN[indexR];
				} else {
					int indexL = indexR - 1;
					double cenR = maxN[indexR];
					double cenL = maxN[indexL];
					if (minN[minP] > maxN[indexL]) {
						cenL = minN[minP];
					}
					//printf("%f %f\n", cenR, cenL);
					ans = (cenR + cenL) / 2.0;
				}
			} else {
				int indexR = minP + cen - curL;
				if ((minL + maxL) % 2 == 1) {
					ans = minN[indexR];
				} else {
					int indexL = indexR - 1;
					if (indexL >= 0) {
						ans = (minN[indexL] + minN[indexR]) / 2.0;
					}
					if(maxN[maxL - 1] > minN[indexL]){
						ans = (maxN[indexL] + minN[indexR]) / 2.0;
					}
				}
			}
		} else {
			if (curL == cen) {
				if (minMax == 0) {//
					if ((minL + maxL) % 2 == 1) {
						ans = maxN[maxP];
					} else {
						double cenR = maxN[maxP];
						double cenL = minN[index - 1];
						if(maxP >= 0 && maxN[maxP - 1] > cenL) {
							cenL = maxN[maxP - 1];
						}
						ans = (cenR + cenL) / 2.0;
					}
				} else {//
					if ((minL + maxL) % 2 == 1) {
						ans = minN[minP];
					} else {
						double cenR = minN[minP];
						double cenL = maxN[index - 1];
						if(minP >= 0 && minN[minP - 1] > cenL) {
							cenL = minN[minP - 1];
						}
						ans = (cenR + cenL) / 2.0;
					}
				}
			} else {
				int indexR = index - (curL - cen);
				if (minMax == 0) {
					if ((minL + maxL) % 2 == 1) {
						ans = minN[indexR];
					} else {
						double cenR = minN[indexR];
						double cenL = minN[indexR - 1];
						if (maxN[maxP] > minN[indexR - 1]) {
							cenL = maxN[maxP];
						}
						ans = (cenR + cenL) / 2.0;
					}
				} else {
					if ((minL + maxL) % 2 == 1) {
						ans = maxN[indexR];
					} else {
						double cenR = maxN[indexR];
						double cenL = maxN[indexR - 1];
						if (minN[minP] > maxN[indexR - 1]) {
							cenL = maxN[maxP];
						}
						ans = (cenR + cenL) / 2.0;
					}
				}
			}
		}
		return ans;
    }
};

int main() {
	vector<int> num1;
	num1.push_back(2);
	//num1.push_back(2);
//	num1.push_back(3);

	vector<int> num2;
	num2.push_back(1);
	num2.push_back(3);
	num2.push_back(4);
//	num2.push_back(10);
//	num2.push_back(11);
//	num2.push_back(13);
//	num2.push_back(15);
//	num2.push_back(21);
//	num2.push_back(22);
//	num2.push_back(23);
//	num2.push_back(24);
//	num2.push_back(25);
//	num2.push_back(26);
//	

	Solution s;
	double ans = s.findMedianSortedArrays(num1, num2);
	cout << ans << endl;
	//cout << s.upper(num1, 0, 3, 4) << endl;
	return 0;
}