码迷,mamicode.com
首页 > 其他好文 > 详细

ACdream原创群赛(16) J

时间:2014-07-12 21:17:15      阅读:182      评论:0      收藏:0      [点我收藏+]

标签:des   style   java   color   strong   os   


Sum
Time Limit: 2000/1000MS (Java/Others) Memory Limit: 128000/64000KB (Java/Others)
SubmitStatus
Problem Description


You are given an N*N digit matrix and you can get several horizontal or vertical digit strings from any position.


For example:


123


456


789


In first row, you can get 6 digit strings totally, which are 1,2,3,12,23,123.


In first column, you can get 6 digit strings totally, which are 1,4,7,14,47,147.


We want to get all digit strings from each row and column, and write them on a paper. Now I wonder the sum of all number on the paper if we consider a digit string as a complete decimal number.


Input


The first line contains an integer N. (1 <= N <= 1000)


In the next N lines each line contains a string with N digit.


Output


Output the answer after module 1,000,000,007(1e9+7)。


Sample Input


3
123
456
789
Sample Output


2784


题目主要是导出公式:

如n行n列的每一行的和sum=1111.....111(n个1)*A1+111...111(n-1个1)*2*A2+.........+11*(n-1)*An-1+1*n*An;

求1111111...111我用到打表减少时间复杂。


AC代码如下:

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#define M 1000000007
#define min(a,b) (a<b?a:b)
using namespace std;

char a[1005][1005];
long long b[1005];

int main()
{
    int n;
    long long i,j;
    for(i=1;i<=1005;i++)
        b[i]=0;
    for(i=1;i<=1005;i++)
        for(j=1;j<=i;j++)
    {
        b[i]=(b[i]*10+1)%M;
    }
    while(~scanf("%d",&n))
    {
        long long sum=0;
        for(i=0;i<n;i++)
        {
            scanf("%s",&a[i]);
            for(j=0;j<n;j++)
                sum=(sum+((((j+1)*((long long)a[i][j]-'0'))*b[n-j])%M))%M;
        }
        for(j=0;j<n;j++)
        {
            for(i=0;i<n;i++)
                sum=(sum+((((i+1)*((long long)a[i][j]-'0'))*b[n-i])%M))%M;
        }
        cout<<sum<<endl;

    }
    return 0;
}


ACdream原创群赛(16) J,布布扣,bubuko.com

ACdream原创群赛(16) J

标签:des   style   java   color   strong   os   

原文地址:http://blog.csdn.net/hanhai768/article/details/37720591

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!