不知道是做着故意放的还是什么原因。总之运行后就会出现问题（奇怪的条目的数量）
function merge(left, right){
var result = [];
while (left.length > 0 && right.length > 0){
if (left[0] < right[0]){
result.push(left.shift());
} else {
result.push(right.shift());
}
}
return result.concat(left).concat(right);
}
function mergeSort(items){
if (items.length == 1) {
return items;
}
var work = [];
for (var i=0, len=items.length; i < len; i++){
work.push([items[i]]);
}
work.push([]); //in case of odd number of items
for (var lim=len; lim > 1; lim = (lim+1)/2){
for (var j=0,k=0; k < lim; j++, k+=2){
work[j] = merge(work[k], work[k+1]);
}
work[j] = []; //in case of odd number of items
}
return work[0];
}问题出在标红的这3块
附上正确代码:
function merge(left, right){
var result = [];
while (left.length > 0 && right.length > 0){
if (left[0] < right[0]){
result.push(left.shift());
} else {
result.push(right.shift());
}
}
return result.concat(left).concat(right);
}
function mergeSort(items){
if (items.length == 1) {
return items;
}
var work = [];
for (var i=0, len=items.length; i < len; i++){
work.push([items[i]]);
}
// work.push([]); //in case of odd number of items
for (var lim=len; lim > 1; lim = lim/2){
for (var j=0,k=0; k < lim; j++, k+=2){
work[j] = merge(work[k], work[k+1]);
}
// work[j] = []; //in case of odd number of items
}
return work[0];
}