随机物品权重算法设计
1、前言
在游戏开发中很多功能按权重随机给东西，比如：掉落、奖励、抽奖等等.....
2、功能
*）支持多个权重进行随机
*）能屏蔽指定权重，防止再次随机到
3、实现
public int weightRandom(BitSet exclude, int... weights) { if (weights == null) { //安全性验证 } int length = weights.length; if (length == 0) { return -1; } if (len == 1) { int w = weights[0]; if (w < 0) { //安全性验证 } else if (w == 0) { return -1; } else { return 0; } } int total = 0; for (int i = 0; i < len; i++) { if (exclude != null && exclude.get(i)) { continue; } int w = weights[i]; total += w; } if (total <= 0) { return -1; } int randomNum = random(1, total), hitIndex = -1, partNum = 0; for (int i = 0; i < len; i++) { if (exclude != null && exclude.get(i)) { continue; } int w = weights[i]; partNum += w; if (partNum >= randomNum) { hitIndex = i; break; } } return hitIndex;}