扫雷游戏

http://icpc.upc.edu.cn/problem.php?cid=1585&pid=7

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<cstdlib>
#include<cmath>
using namespace std;
int f,i,j,k,l,b[100000],n,m,ans,a[100000];
int main(){
   scanf("%d",&n);
   for (i=1;i<=n;i++)
    scanf("%d",&a[i]);
   b[1]=0;
   f=0;
   b[2]=a[1]-b[1];
   for (i=3;i<=n;i++){
    b[i]=a[i-1]-b[i-1]-b[i-2];
    if (b[i]>1) {
       f=1;
       break;
    }
   }
   if (b[n]!=a[n]-b[n-1]) f=1;
   if (f){
   b[1]=1;
   b[2]=a[1]-b[1];
   for (i=3;i<=n;i++)
    b[i]=a[i-1]-b[i-1]-b[i-2];
   }
   for (i=1;i<=n;i++){
    if (b[i]) ans++;
    printf("%d",b[i]);
   }
   printf("\n");
   printf("%d\n",ans);
}