方法一、遍歷元素,逐項尋找子數組
方法二、雙指針法
i,j開始都指向0;
j開始右移,若s(i,j)的和大於等於target,則減去arr[i],i右移,直至s(i,j)小於target;
j繼續右移,同樣操作,直至最後;
int minSubArrayLen(int s, int *nums, int numsSize) {
if (numsSize == 0) {
return 0;
}
int ans = INT_MAX;
int start = 0, end = 0;
int sum = 0;
while (end < numsSize) {
sum += nums[end];
while (sum >= s) {
ans = fmin(ans, end - start + 1);
sum -= nums[start];
start++;
}
end++;
}
return ans == INT_MAX ? 0 : ans;
}