static int findMissingNumber(int start, int end, List<Integer> list) {
int last = 0;
for (int i : list) {
if (last != 0 && i - 1 != last) { // 如果减1不等于上一个数,被删除的就是上一个了
return i - 1;
}
last = i;
}
return 0;
}
练习2:
static int findMissingNumber(int start, int end, List<Integer> list) {
// 等差數列求和
int sum = (start + end) * (end - start+1) / 2;
// 遍历数组并减掉
for (int i : list) {
sum -= i;
}
// 剩下的数就是被删除的数
return sum;
}
Shuaixr2000
练习1:
练习2: