题解 | #DNA序列#

let arr = [];
while(line = readline()) {
    let num = readline();
    for (let i=0; i<=line.length - num; i++){ //先切片
        arr.push(line.substr(i, num));
    }
}
let maxRate = 0;
let maxRateStr;
for (let item of arr) {
    let gN = item.match(/G/g) ? item.match(/G/g).length : 0;
    let cN = item.match(/C/g) ? item.match(/C/g).length : 0;
    let rate = (gN + cN) / item.length;
    if (rate > maxRate) {    //获取GC率最高的，因为用的大于，即使评分一样也不会传入
        maxRate = rate;
        maxRateStr = item;
    }
}
print(maxRateStr)