Codeforces Round #436 D.Make a Permutation!（贪心）

题目链接：Make a Permutation!

#include <iostream>#include <cstdio>#include <fstream>#include <algorithm>#include <cmath>#include <deque>#include <vector>#include <queue>#include <string>#include <cstring>#include <map>#include <stack>#include <set>#define Max(a,b) a>b?a:b#define Min(a,b) a>b?b:a#define mem(a,b) memset(a,b,sizeof(a))using namespace std;typedef long long ll;int dir[4][2]= {{1,0},{-1,0},{0,1},{0,-1}};const double eps = 1e-6;const double Pi = acos(-1.0);const int INF=0x3f3f3f3f;const int maxn = 2e5+10;int num[maxn],arr[maxn],flag[maxn];int kind[maxn],cnt;int main(){    int n,x;    while(scanf("%d",&n) != EOF){        mem(num,0);        mem(flag,0);        for(int i = 0; i < n; i++){            scanf("%d",&x);            arr[i] = x;            num[x]++;        }        cnt = 0;        for(int i = 1; i <= n; i++){            if(!num[i]) kind[cnt++] = i;        }        printf("%d\n",cnt);        cnt = 0;        for(int i = 0; i < n; i++){            if(num[arr[i]] != 1){                if(kind[cnt] < arr[i] || flag[arr[i]]){                    num[arr[i]]--;                    arr[i] = kind[cnt];                    cnt++;                }else{                    flag[arr[i]] = 1;                }            }        }        printf("%d",arr[0]);        for(int i = 1; i < n; i++){            printf(" %d",arr[i]);        }        printf("\n");    }    return 0;}