codeforces 320A. Magic Numbers

最新推荐文章于 2020-10-04 23:13:36 发布

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#codeforces

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <math.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
#define ll long long
#define ls rt<<1
#define rs ls1
#define lson l,mid,ls
#define rson mid+1,r,rs
#define middle (l+r)>>1
#define eps (1e-9)
#define clr_all(x,c) memset(x,c,sizeof(x))
#define clr(x,c,n) memset(x,c,sizeof(x[0])*(n+1))
#define MOD 1000000007
#define inf 100000007
#define pi acos(-1.0)
#define M 200000+5
int main(){
int i,j,n,flag;
char s[15];
while(~scanf("%s",&s)){
n=strlen(s);
i=0;flag=0;
while(i<n){
if(s[i]=='1'&&s[i+1]=='4'&&s[i+2]=='4')i+=3;
else if(s[i]=='1'&&s[i+1]=='4')i+=2;
else if(s[i]=='1')i+=1;
else {
flag=1;
break;
}
// printf("%d\n",i);
}
if(flag==0)puts("YES");
else puts("NO");
}
return 0;
}