sku组合查询算法探讨-之JS实现示例

/* 后端数据 */
var data = {
"10;20;30": {
price: 5,
count: 1
},
"10;20;31": {
price: 10,
count: 2
},
"11;20;30": {
price: 5,
count: 1
},
"10;21;31": {
price: 10,
count: 2
},
"10;21;32": {
price: 10,
count: 9
}
}

var myData = {},

//可选项key值
keys = [
[10, 11, 12],
[20, 21],
[30, 31, 32]
];

//获取 key的库存量

function getNum(key) {
var result = 0,

i, j, m,

items, n = [];

//检查是否已计算过
if (typeof myData[key] != 'undefined') {
return myData[key];
}

items = key.split(";");

//已选择数据是最小路径，直接从已端数据获取
if (items.length === keys.length) {
return data[key] ? data[key].count : 0;
}

//拼接子串
for (i = 0; i < keys.length; i++) {
for (j = 0; j < keys[i].length && items.length > 0; j++) {
if (keys[i][j] == items[0]) {
break;
}
}

if (j < keys[i].length && items.length > 0) {
//找到该项，跳过
n.push(items.shift());
} else {
//分解求值
for (m = 0; m < keys[i].length; m++) {
result += getNum(n.concat(keys[i][m], items).join(";"));
}
break;
}
}

//缓存
myData[key] = result;
return result;
}

document.write(getNum("10") + ";"); //输出14
document.write(getNum("11") + ";"); //输出1
document.write(getNum("10;21") + ";"); //输出11
document.write(getNum("21;31") + ";"); //输出2​