Median of Two Sorted Arrays

標籤：java   leetcode   數組   

題目

There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

方法

轉換為尋找第k大的數。參考：http://blog.csdn.net/zxzxy1988/article/details/8587244

private int findValue(int A[], int leftA, int[] B, int leftB, int k) {if (A.length - leftA > B.length - leftB) {return findValue(B, leftB, A, leftA, k);} if (A.length - leftA == 0) {return B[k - 1];}if (k == 1) {return Math.min(A[leftA], B[leftB]);}int a = Math.min(k / 2, A.length - leftA);int b = k - a;if (A[a + leftA - 1] == B[b + leftB - 1]) {return A[a + leftA - 1];} else if (A[a + leftA - 1] > B[b + leftB - 1]){return findValue(A, leftA, B, leftB + b, k - b);} else {return findValue(A, leftA + a, B, leftB, k - a);}}    public double findMedianSortedArrays(int A[], int B[]) {    int lenA = A.length;    int lenB = B.length;    int sum = lenA + lenB;    if ((sum & 1) == 1) {    return findValue(A, 0, B, 0, sum / 2 + 1);    } else {    return (findValue(A, 0, B, 0, sum / 2) + findValue(A, 0, B, 0, (sum/2 + 1))) / 2.0;    }    }