@@ -290,10 +290,11 @@ func search(nums []int, target int) int {
290290 */
291291var search = function (nums , target ) {
292292 // right是数组最后一个数的下标,num[right]在查找范围内,是左闭右闭区间
293- let left = 0 , right = nums .length - 1 ;
293+ let mid, left = 0 , right = nums .length - 1 ;
294294 // 当left=right时,由于nums[right]在查找范围内,所以要包括此情况
295295 while (left <= right) {
296- let mid = left + Math .floor ((right - left)/ 2 );
296+ // 位运算 + 防止大数溢出
297+ mid = left + ((right - left) >> 1 );
297298 // 如果中间数大于目标值,要把中间数排除查找范围,所以右边界更新为mid-1;如果右边界更新为mid,那中间数还在下次查找范围内
298299 if (nums[mid] > target) {
299300 right = mid - 1 ; // 去左面闭区间寻找
@@ -316,10 +317,11 @@ var search = function(nums, target) {
316317 */
317318var search = function (nums , target ) {
318319 // right是数组最后一个数的下标+1,nums[right]不在查找范围内,是左闭右开区间
319- let left = 0 , right = nums .length ;
320+ let mid, left = 0 , right = nums .length ;
320321 // 当left=right时,由于nums[right]不在查找范围,所以不必包括此情况
321322 while (left < right) {
322- let mid = left + Math .floor ((right - left)/ 2 );
323+ // 位运算 + 防止大数溢出
324+ mid = left + ((right - left) >> 1 );
323325 // 如果中间值大于目标值,中间值不应在下次查找的范围内,但中间值的前一个值应在;
324326 // 由于right本来就不在查找范围内,所以将右边界更新为中间值,如果更新右边界为mid-1则将中间值的前一个值也踢出了下次寻找范围
325327 if (nums[mid] > target) {
@@ -340,9 +342,10 @@ var search = function(nums, target) {
340342
341343``` typescript
342344function search(nums : number [], target : number ): number {
343- let left: number = 0 , right: number = nums .length - 1 ;
345+ let mid : number , left: number = 0 , right: number = nums .length - 1 ;
344346 while (left <= right ) {
345- let mid: number = left + Math .floor ((right - left ) / 2 );
347+ // 位运算 + 防止大数溢出
348+ mid = left + ((right - left ) >> 1 );
346349 if (nums [mid ] > target ) {
347350 right = mid - 1 ;
348351 } else if (nums [mid ] < target ) {
@@ -359,9 +362,10 @@ function search(nums: number[], target: number): number {
359362
360363``` typescript
361364function search(nums : number [], target : number ): number {
362- let left: number = 0 , right: number = nums .length ;
365+ let mid : number , left: number = 0 , right: number = nums .length ;
363366 while (left < right ) {
364- let mid: number = left + Math .floor ((right - left ) / 2 );
367+ // 位运算 + 防止大数溢出
368+ mid = left + ((right - left ) >> 1 );
365369 if (nums [mid ] > target ) {
366370 right = mid ;
367371 } else if (nums [mid ] < target ) {
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