2.1Sorting A Three-Valued Sequence

n个取值为[1，3]的数，要求将他们按增序排序，无难度

 

#include<iostream>#include<fstream>#include<string>#include<memory.h>#include<cstdio>#include<cmath>#include<algorithm>#include<queue>#include<vector>using namespace std;ifstream fin("sort3.in");ofstream fout("sort3.out");int n;int in[1001];int cnt[3];int f1=0;int res=0;int main(){int i,j;memset(cnt,0,sizeof(cnt));fin>>n;for(i=0;i<n;i++){fin>>in[i];cnt[in[i]-1]++;}for(i=0;i<cnt[0];i++){if(in[i]!=1) f1++;}res+=f1;for(i=n-1;i>=cnt[0];i--){if(f1==0)break;if(in[i]==1){bool flag=false;for(j=0;j<cnt[0];j++){if(in[j]==3){in[i]=3,in[j]=1;flag=true;break;}}if(!flag){for(j=0;j<cnt[0];j++){if(in[j]==2){in[i]=2,in[j]=1;break;}}}f1--;}}/*for(i=0;i<n;i++){fout<<in[i]<<" ";}fout<<endl;fout<<res<<endl;*/for(i=cnt[0],j=0;j<cnt[1];i++,j++){if(in[i]!=2) {res++;}}fout<<res<<endl;return 0;}