PAT 1067

#include<cstdio>#include<algorithm>#include<stdlib.h>#include<cstring>using namespace std;int c;int p[100010];int main(){int n;scanf("%d",&n);int left=n-1;for(int i=0;i<n;i++){scanf("%d",&c);p[c]=i;if(c==i&&c!=0)left--;}int time=0;int k=1;while(left>0){if(p[0]==0){while(k<n){if(p[k]!=k){swap(p[0],p[k]);time++;break;}k++;}}while(p[0]!=0){swap(p[0],p[p[0]]);time++;left--;}}printf("%d",time);system("pause");return 0;}