Codeforces Round #205 (Div. 2)

A

 1 #include <iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<stdlib.h>
 6 #include<vector>
 7 using namespace std;
 8 int a[110];
 9 int main()
10 {
11     int i,j,n,u,v;
12     int s1=0,s2=0,num=0;
13     scanf("%d",&n);
14     for(i = 1; i <= n ; i++)
15     {
16         scanf("%d%d",&u,&v);
17         if((u%2==0&&v%2!=0)||(u%2!=0&&v%2==0))
18         num++;
19         s1+=u;
20         s2+=v;
21     }
22     if(s1%2==0&&s2%2==0)
23     {
24         printf("0\n");
25     }
26     else if(s1%2!=0&&s2%2!=0)
27     {
28         if(num)
29         printf("1\n");
30         else
31         printf("-1\n");
32     }
33     else
34     printf("-1\n");
35     return 0;
36 }
View Code

B 构造一下。。乱弄了下

 1 #include <iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<stdlib.h>
 6 #include<vector>
 7 using namespace std;
 8 #define N 210
 9 int n,a[N],f[N],o[N];
10 int main()
11 {
12     int i,j;
13     scanf("%d",&n);
14     for(i =1; i <= 2*n ; i++)
15     {
16         scanf("%d",&a[i]);
17         f[a[i]]++;
18     }
19     int s1=0,s2=0,num=0;
20     for(i = 10 ; i <= 99 ; i++)
21     if(f[i]>=2)
22     {
23         if(f[i]%2==0)
24         {
25             s1+=f[i]/2-1;
26         }
27         else
28         {
29             s1+=f[i]/2-1;
30             s2++;
31         }
32     }
33     else if(f[i]==1)
34     num++;
35     int k1 = s2/2,k2 = n-s1-s2/2;
36     int ans = (n-s1-s2/2)*(n-s1-(s2-s2/2));
37     num = (num+1)/2;
38    // printf("")
39     for(i = 1 ; i <= 2*n ; i++)
40     {
41         if(f[a[i]]==1)
42         {
43             o[i] = 1;
44             num--;
45         }
46         if(num==0)
47         break;
48     }
49     for(i = 1; i <= 2*n ; i++)
50     {
51         if(f[a[i]]>=2)
52         {
53             int kk;
54             if(k1&&f[a[i]]%2!=0)
55             {
56                 kk = f[a[i]]/2+1;
57                 k1--;
58             }
59             else
60             kk = f[a[i]]/2;
61             for(j = 1; j <= 2*n ; j++)
62             {
63                 if(a[j]==a[i])
64                 {
65                     kk--;
66                     o[j] = 1;
67                 }
68                 if(kk==0)
69                 break;
70             }
71             f[a[i]] = 0;
72         }
73     }
74     printf("%d\n",ans);
75     for(i = 1; i < 2*n ; i++)
76     if(o[i]==1)
77     printf("1 ");
78     else
79     printf("2 ");
80     if(o[2*n]==1)
81     printf("1\n");
82     else
83     printf("2\n");
84     return 0;
85 }
View Code

C  枚举1的位置 变为0后 后面全取1  一个很2的错误WA了2 次

 1 #include <iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<stdlib.h>
 6 #include<vector>
 7 using namespace std;
 8 #define N 100010
 9 #define LL __int64
10 int a[N];
11 LL sum[N];
12 char s[N];
13 int main()
14 {
15     int i,j,n;
16     scanf("%d",&n);
17     for(i = 0; i < n ; i++)
18     scanf("%d",&a[i]);
19     cin>>s;
20     int k=-1;
21     LL ss=0,maxz=0;
22     for(i = 0 ; i < n ;i++)
23     {
24         if(s[i]=='1')
25         {
26             ss+=a[i];
27             if(i==0)
28             sum[i] = a[i];
29             else
30             sum[i]=sum[i-1]+a[i];
31             k = i;
32         }
33         else
34         if(i!=0)
35         sum[i] = sum[i-1];
36     }
37     if(k==-1)
38     printf("0\n");
39     else
40     {
41         maxz = max(maxz,ss);
42         int tsum=0;
43         for(i = 0 ; i <= k ; i++)
44         {
45             if(s[i]=='1')
46             {
47                 maxz = max(sum[k]-sum[i]+tsum,maxz);
48             }
49             tsum+=a[i];
50         }
51         printf("%I64d\n",maxz);
52     }
53     return 0;
54 }
View Code

 

posted @ 2013-10-11 15:39  _雨  阅读(214)  评论(0)  编辑  收藏  举报