Answer 1

暴力一点吧。

var intersect = function(nums1, nums2) {
    let result = [];
    for(let i = 0; i < nums1.length; i++) {
        for(let j = 0; j < nums2.length; j++) {
            if(nums1[i] == nums2[j]) {      
                nums2.splice(j,1);
                result.push(nums1[i]);
                break;
            }
        }
    }
    return result;
}

Answer 2

const findStr = (str, t) => {
	if (t.length > str.length) return -1;
	for (let index = 0; index < str.length - t.length + 1; index++) {
		const cur = str.slice(index, index + t.length);
		if (cur === t) {
			return index;
		}
	}
};

console.log(find('asdfg', 'sdf'));