Leetcode2

Leetcode2

• 209.长度最小的子数组
• 59.螺旋矩阵II

209.长度最小的子数组

Java

classSolution{publicintminSubArrayLen(inttarget,int[]nums){intresult=Integer.MAX_VALUE;intl=nums.length;ints=0;intslow=0;for(intfast=0;fast<l;fast++){s=s+nums[fast];while(s>=target){if(result>fast-slow+1){result=fast-slow+1;}s=s-nums[slow];slow++;}}if(result==Integer.MAX_VALUE){return0;}returnresult;}}

采用双指针，fast代表快指针，每次移动后检查当前的和是否大于target，如果大于，slow慢指针向前移动，并减去相应的值.

59.螺旋矩阵II

classSolution{publicint[][]generateMatrix(intn){intx=0,y=0;intbound=1;int[][]nums=newint[n][n];inti,j;intloop=1;intnum=1;if(n%2==1){nums[n/2][n/2]=n*n;}while(loop<=n/2){for(j=y;j<n-bound;j++){nums[x][j]=num++;}for(i=x;i<n-bound;i++){nums[i][j]=num++;}for(;j>y;j--){nums[i][j]=num++;}for(;i>x;i--){nums[i][j]=num++;}x++;y++;loop++;bound++;}returnnums;}}