hdu3359 高斯消元(实数)模板:给定高斯模糊后的矩阵求原矩阵

额很裸的现在才看到==

就是把原矩阵设N×M个未知量直接代入高斯消元==

目前手打基本上无压力了,下面把5009做了高斯消元可以放一下了==

(突然发现两个问题,整数的高消还没怎么写过?小数精度大的还没看到过?额这周末前弄好

 1 #include<stdio.h>
 2 #include<math.h>
 3 #include<string.h>
 4 #include<algorithm>
 5 using namespace std;
 6 #define eps 1e-10
 7 int n,m;
 8 int cal(int i,int j)
 9 {
10   return (i-1)*m+j;
11 }
12 double g[105][105],x[105],a[15][15];
13 int row,col;
14 int guass()
15 {
16   int tr,tc,i,j,max_r;
17   for (tr=1,tc=1;tc<=col;tc++)
18   {
19     max_r=tr;
20     for (i=tr;i<=row;i++)
21       if (fabs(g[i][tc])>fabs(g[max_r][tc])) max_r=i;
22     if (fabs(g[max_r][tc])<eps) return 0;
23     if (max_r!=tr)
24     {
25       for (j=tc;j<=col;j++) swap(g[tr][j],g[max_r][j]);
26       swap(x[tr],x[max_r]);
27     }
28     for (j=tc+1;j<=col;j++) g[tr][j]/=g[tr][tc];
29     x[tr]/=g[tr][tc]; g[tr][tc]=1;
30     for (i=1;i<=row;i++)
31       if (i!=tr)
32       {
33         for (j=tc+1;j<=col;j++) g[i][j]-=g[i][tc]*g[tr][j];
34         x[i]-=g[i][tc]*x[tr]; g[i][tc]=0;
35       }
36     tr++;
37   }
38   return 1;
39 }
40 int main()
41 {
42   int judge=0,d,i,j,id,tmp_id,ans,ti,tj;
43   while (~scanf("%d%d%d",&m,&n,&d)&&n)
44   {
45     memset(g,0,sizeof(g));
46     memset(x,0,sizeof(x));
47     for (i=1;i<=n;i++)
48       for (j=1;j<=m;j++) scanf("%lf",&a[i][j]);
49     for (i=1;i<=n;i++)
50       for (j=1;j<=m;j++)
51       {
52         id=cal(i,j);
53         ans=0;
54         for (ti=1;ti<=n;ti++)
55           for (tj=1;tj<=m;tj++)
56             if (abs(i-ti)+abs(j-tj)<=d) ans++;
57         for (ti=1;ti<=n;ti++)
58           for (tj=1;tj<=m;tj++)
59             if (abs(i-ti)+abs(j-tj)<=d){
60               tmp_id=cal(ti,tj);
61               g[id][tmp_id]+=1.0/ans;
62             }
63         x[id]+=a[i][j];
64       }
65     row=col=n*m;
66     guass();
67     if (judge) printf("\n"); judge=1;
68     for (i=1;i<=n;i++)
69       for (j=1;j<=m;j++)
70       {
71         id=cal(i,j);
72         printf("%8.2lf",x[id]);
73         if (j==m) printf("\n");
74       }
75   }
76   return 0;
77 }
View Code

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3359

posted on 2015-03-06 00:08  xiao_xin  阅读(167)  评论(0编辑  收藏  举报

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