我需要找到所需的最小交换数，以使所有0和所有1在一起.
I need to find the minimum number of swaps required such that all the 0s and all the 1s are together.
这是我的代码:
class GFG { static int minSwaps(int arr[], int n) { int noOfOnes = 0; for (int i = 1; i <= n; i++) { if (arr[i] == 1) noOfOnes++; } int x = noOfOnes; int maxOnes = Integer.MIN_VALUE; int preCompute[] = new int[n]; if (arr[0] == 1) preCompute[0] = 1; for (int i = 2; i < n; i++) { if (arr[i] == 1) { preCompute[i] = preCompute[i - 1] + 1; } else { preCompute[i] = preCompute[i - 1]; } } for (int i = x - 1; i < n; i++) { if (i == (x - 1)) { noOfOnes = preCompute[i]; } else { noOfOnes = preCompute[i] - preCompute[i - x]; } if (maxOnes < noOfOnes) maxOnes = noOfOnes; } int noOfZeroes = x - maxOnes; return noOfZeroes; } public static void main (String[] args) { Scanner s = new Scanner(System.in); int t = s.nextInt(); for (int test = 1; test <= t; test++) { int n = s.nextInt(); int[] a = new int[n]; for (int j = 1; j <= n; j++) { a[j] = s.nextInt(); } System.out.println(minSwaps(a, n)); System.out.println("\n"); } } }我收到了 ArrayIndexOutOfBoundsException :
error : Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4 at GFG.main(solution.java:56) 推荐答案您似乎正在尝试冒泡.因此，我从Wikipedia复制了 bubblesort伪代码实现，并用一个计数器进行了增强:
It looks like you're trying to do bubblesort. So I copied this bubblesort pseudocode implementation off of Wikipedia and augmented it with a counter:
bubbleSort(Array A) swap_counter = 0 // start at 0 for (n=A.size; n>1; --n){ for (i=0; i<n-1; ++i){ if (A[i] > A[i+1]){ A.swap(i, i+1) swap_counter++ // count a swap } } } return swap_counter // return the result