Java: How to randomly go through an array?

What you are looking for is shuffle\n\ntry this-\n\n// Create a list\nList list = new ArrayList();\n\n// Add elements to list\n\n// Shuffle the elements in the list\nCollections.shuffle(list);\n\n// Create an array\nString[] array = new String[]{\"a\", \"b\", \"c\"};\n\n// Shuffle the elements in the array\nCollections.shuffle(Arrays.asList(array));\n",

Just shuffle the array and then iterate over it.\n\nCollections.shuffle(Arrays.asList(yourArrayReference));\n",

Here is a time and space efficient way to do it. \n\nimport java.util.Enumeration;\nimport java.util.Random;\n\npublic class RandomPermuteIterator implements Enumeration<Long> {\n int c = 1013904223, a = 1664525;\n long seed, N, m, next;\n boolean hasNext = true;\n\n public RandomPermuteIterator(long N) throws Exception {\n if (N <= 0 || N > Math.pow(2, 62)) throw new Exception(\"Unsupported size: \" + N);\n this.N = N;\n m = (long) Math.pow(2, Math.ceil(Math.log(N) / Math.log(2)));\n next = seed = new Random().nextInt((int) Math.min(N, Integer.MAX_VALUE));\n }\n\n public static void main(String[] args) throws Exception {\n RandomPermuteIterator r = new RandomPermuteIterator(100);\n while (r.hasMoreElements()) System.out.print(r.nextElement() + \" \");\n }\n\n @Override\n public boolean hasMoreElements() {\n return hasNext;\n }\n\n @Override\n public Long nextElement() {\n next = (a * next + c) % m;\n while (next >= N) next = (a * next + c) % m;\n if (next == seed) hasNext = false;\n return next;\n }\n}\n",