java 查找list中重復(fù)數(shù)據(jù)實(shí)例詳解
需求:
查找一個List集合中所有重復(fù)的數(shù)據(jù),重復(fù)的數(shù)據(jù)可能不止一堆,比如:aa, bb, aa, bb, cc , dd, aa這樣的數(shù)據(jù)。如果有重復(fù)數(shù)據(jù),則給這些重復(fù)數(shù)據(jù)加上編號,上述數(shù)據(jù)改為:aa1, bb1, aa2, bb2, cc, dd.
算法如下:
public static void same(List<String> list) { String [] indexArr ; Map<String, String> map = new HashMap<String, String>(); for (int i = 0; i < list.size(); i++) { String key = list.get(i); String old = map.get(key); if (old != null) { map.put(key, old + "," + (i + 1)); } else { map.put(key, "" + (i + 1)); } } Iterator<String> it = map.keySet().iterator(); int index = -1; while (it.hasNext()) { String key = it.next(); String value = map.get(key); if (value.indexOf(",") != -1) { System.out.println(key + " 重復(fù),行: " + value); indexArr = value.split(","); for (int i = 0; i < indexArr.length; i++) { index = Integer.parseInt(indexArr[i])-1; list.set(index, list.get(index)+(1+i)); } } } for (String val : list) { System.out.println("val = "+val); } System.out.println(".................."); }感謝閱讀,希望能幫助到大家,謝謝大家對本站的支持!
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