1 function checkCashRegister(price, cash, cid) {
  2   var change; 
  3   var sumCid;
  4   
  5 // Here is your change, ma‘am.
  6   var obj = {
  7     penny:     cid[0][1],
  8     nickel:    cid[1][1],
  9     dime:      cid[2][1],
 10     quarter:   cid[3][1],
 11     one:       cid[4][1],
 12     five:      cid[5][1],
 13     ten:       cid[6][1],
 14     twenty:    cid[7][1],    
 15     oneHundred:cid[8][1]
 16   };
 17 
 18   //购买价格(price), 付款金额 (cash), 收银机中零钱 (cid)
 19   change = cash - price;
 20   //console.log("typeof(change):", typeof(change)); //number
 21   //console.log("change:", change);
 22   
 23   sumCid = 
 24     obj.penny + 
 25     obj.nickel + 
 26     obj.dime + 
 27     obj.quarter + 
 28     obj.one + 
 29     obj.five + 
 30     obj.ten + 
 31     obj.twenty + 
 32     obj.oneHundred;
 33   
 34   sumCid = Number(sumCid.toFixed(2));  //保留两位小数
 35 
 36   //console.log(typeof(sumCid)); //number
 37   //console.log("sumCid:", sumCid);
 38 
 39   if (sumCid < change) {
 40       //console.log("sumCid小于change！");
 41     return "Insufficient Funds";  //余额不足
 42   } 
 43   else if (sumCid === change) {
 44       //console.log("sumCid等于change！");
 45     return "Closed";
 46   } 
 47   else {
 48       // 1.零钱不够,返回余额不足
 49       // 2.零钱足够,找回零钱
 50       //console.log("sumCid大于change!");
 51       overChange(change, cid, sumCid);
 52   } 
 53 }
 54 
 55 function overChange(change, arr, sumCid) {
 56   var array = [];
 57   var len = arr.length;
 58   
 59   for (var i = len - 1; i >= 0; i--) {
 60       if (arr[i][1] === 0) continue;
 61 
 62       if (arr[i][1] < change) {
 63         array.push(arr[i]);
 64       change -= arr[i][1];
 65       change = Number(change.toFixed(2));
 66       //console.log("current change:", change);
 67       }
 68 
 69       else if (arr[i][1] > change) {
 70       var x = arr[i][0];  // 取得零钱名称
 71         //console.log("x:", x);
 72         var y = 0;
 73 
 74         switch(x) {
 75           case "ONE HUNDRED":
 76             y = Math.floor(change / 100) * 100;
 77             break;
 78           case "TWENTY":
 79             y = Math.floor(change / 20) * 20;
 80             break;
 81           case "TEN":
 82             y = Math.floor(change / 10) * 10;
 83             break;
 84           case "FIVE":
 85               y = Math.floor(change / 5) * 5;
 86               break;
 87             case "ONE":
 88               y = Math.floor(change / 1);
 89               break;
 90             case "QUARTER":
 91               y = Math.floor(change / 0.25) * 0.25;
 92               break;
 93             case "DIME":
 94               y = Math.floor(change / 0.10) * 0.10;
 95               break;
 96             case "NICKEL":
 97               y = Math.floor(change / 0.05) * 0.05;
 98               break;
 99             case "PENNY":
100               y = Math.floor(change / 0.01) * 0.01;
101               break;
102        }
103 
104         console.log(y);
105         console.log(sumCid - arr[i][1] < change);
106 
107         if (y === 0 && sumCid - arr[i][1] < change) {
108         //console.log("Insufficient Funds");
109         return "Insufficient Funds";              
110         }
111 
112         else if (y === 0) {
113           continue;
114         }
115 
116         else {
117             if (y < 1) {
118                 y = y;
119             }           
120         var array1 = [];
121           array1.push(arr[i][0]);
122           array1.push(y);
123           array.push(array1);
124         change -= y;
125         change = Number(change.toFixed(2));
126         //console.log("current change:", change);
127       }
128       }
129   }
130 
131   if (change === 0) {
132       //console.log("array:", array);
133       return array;
134   }
135   else {
136       //console.log("Insufficient Funds");
137       return "Insufficient Funds";
138   }
139   
140 }
141 
142 checkCashRegister(3.26, 100.00, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.10], ["QUARTER", 4.25], ["ONE", 90.00], ["FIVE", 55.00], ["TEN", 20.00], ["TWENTY", 60.00], ["ONE HUNDRED", 100.00]]);