PAT 甲级 1144  The Missing Number

1144 The Missing Number （20 point(s)）

Given N integers, you are supposed to find the smallest positive integer that is NOT in the given list.

Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N (≤105). Then N integers are given in the next line, separated by spaces. All the numbers are in the range of int.

Output Specification:

Print in a line the smallest positive integer that is missing from the input list.

Sample Input:

10
5 -25 9 6 1 3 4 2 5 17

Sample Output:

7

经验总结：

emmm  简单的划水题，不多说啦~

AC代码

#include <cstdio>
const int maxn=100010;
bool flag[maxn]={false};
int main()
{
  int n,t;
  scanf("%d",&n);
  for(int i=0;i<n;++i)
  {
    scanf("%d",&t);
    if(t<maxn&&t>0)
      flag[t]=true;
  }
  for(int i=1;i<maxn;++i)
    if(flag[i]==false)
    {
      printf("%d\n",i);
      break;
    }
  return 0;
}