使用JavaScript檢查缺數
當一個數:−
至少有三位數,且
能被其首位數字和末位數字組合成的數整除
例如
1053 is a gapful number because it has 4 digits and it is exactly divisible by 13. 135 is a gapful number because it has 3 digits and it is exactly divisible by 15.
我們的工作是編寫一個程式,為我們提供的輸入數字返回其最近的缺數。
讓我們編寫程式碼 −
const n = 134; //receives a number string and returns a boolean const isGapful = (numStr) => { const int = parseInt(numStr); return int % parseInt(numStr[0] + numStr[numStr.length - 1]) === 0; }; //main function -- receives a number, returns a number const nearestGapful = (num) => { if(typeof num !== 'number'){ return -1; } if(num <= 100){ return 100; } let prev = num - 1, next = num + 1; while(!isGapful(String(prev)) && !isGapful(String(next))){ prev--; next++; }; return isGapful(String(prev)) ? prev : next; }; console.log(nearestGapful(n));
控制檯中的輸出將是 −
135
廣告