//10进制 转为26进制
function num10ToNum26(num){
    let chars='abcdefghijklmnopqrstuvwxyz'
    let charArr=chars.split('');
    let targets=[];
    while (num>0){
        let yn= num%26;
        targets.push(yn);
        num=(num-yn)/26;
    }
    targets.reverse();
    let target='';
    for(let i=0;i<targets.length;i++){
        target+=charArr[targets[i]];
    }
    console.log('targets:'+JSON.stringify(targets));
    return target;
}

function num26TNum10(str){
    let chars='abcdefghijklmnopqrstuvwxyz'
    let charArr=chars.split('');

    let strs=str.split('');
    let total=0;
    for(let i=0;i<strs.length;i++){
        let num=0;
        for(let j=0;j<charArr.length;j++){
            if(charArr[j]===strs[i]){
                num=j;
                break;
            }
        }
        let dd=1;
        for(let m=0;m<strs.length-i-1;m++){
            dd=dd*26;
        }
        //取得num
        total+=(num*dd);
    }
    return total;
}