codeforces #336 div 2 B. Hamming Distance Sum
http://codeforces.com/contest/608/problem/B 题意：给定两个字符串a,b，问b中的每个连续的长度为a的子串与a的哈密顿距离的和是多少。哈密顿距离是对应位置的字符的差的绝对值的和。由于是01串，也就是字符不同的位置数。 思路：类似前缀和。0和1分别搞。注意开long long
/* ***********************************************
Author :111qqz
Created Time :2015年12月24日 星期四 00时32分33秒
File Name :code/cf/#336/B.cpp
************************************************ */
1#include <cstdio>
2#include <cstring>
3#include <iostream>
4#include <algorithm>
5#include <vector>
6#include <queue>
7#include <set>
8#include <map>
9#include <string>
10#include <cmath>
11#include <cstdlib>
12#include <ctime>
13#define fst first
14#define sec second
15#define lson l,m,rt<<1
16#define rson m+1,r,rt<<1|1
17#define ms(a,x) memset(a,x,sizeof(a))
18typedef long long LL;
19#define pi pair < int ,int >
20#define MP make_pair
1using namespace std;
2const double eps = 1E-8;
3const int dx4[4]={1,0,0,-1};
4const int dy4[4]={0,-1,1,0};
5const int inf = 0x3f3f3f3f;
6const int N=3E5+7;
7int la,lb;
8char a[N],b[N];
9int sum0[N],sum1[N];
10int main()
11{
12 #ifndef ONLINE_JUDGE
13 freopen("code/in.txt","r",stdin);
14 #endif
15 ms(sum0,0);
16 ms(sum1,0);
17 scanf("%s",a);
18 scanf("%s",b);
19 la = strlen(a);
20 lb = strlen(b);
21 int sum = 0 ;
22 if (la==1)
23 {
24 for ( int i = 0 ; i < lb ; i++)
25 {
26 if (b[i]!=a[0]) sum++;
27 }
28 cout<<sum<<endl;
29 return 0;
}
1 for ( int i = 0 ; i < lb ; i++)
2 {
3 if (b[i]=='0')
4 {
5 sum0[i+1] = sum0[i]+1;
6 sum1[i+1] = sum1[i];
7 }
8 else
9 {
10 sum1[i+1] = sum1[i] +1;
11 sum0[i+1] = sum0[i];
12 }
13 }
14// for ( int i = 1 ; i <= lb ; i++)
15// cout<<sum0[i]<<" "<<sum1[i]<<endl;
16 LL ans = 0;
17 for (int i= 0 ; i < la ; i++)
18 {
19 if (a[i]=='0')
20 {
21 ans+=LL(sum1[lb-la+i+1]-sum1[i]);
22 }
23 else
24 {
25 ans+=LL(sum0[lb-la+i+1]-sum0[i]);
26 }
27// cout<<ans<<endl;
28 }
cout<<ans<<endl;
1 #ifndef ONLINE_JUDGE
2 fclose(stdin);
3 #endif
4 return 0;
5}