高斯消元

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int n;
 4 double res[111],G[111][111];
 5 void guess(int ii)
 6 {
 7     int i,j;
 8     double first=G[ii][ii],first1;
 9     for(i=ii+1;i<=n;i++)
10     {
11         first1=-G[i][ii];
12         for(j=ii;j<=n+1;j++)G[i][j]+=((G[ii][j]*first1)/first);
13     }
14 }
15 double r_guess(int ii)
16 {
17     int i=ii;
18     double sum=G[ii][n+1];
19     while(i<=n)i++,sum-=(G[ii][i]*res[i]);
20     return sum/G[ii][ii];
21 }
22 int main()
23 {
24     int i,j;
25     scanf("%d",&n);
26     for(i=1;i<=n;i++)
27     {
28         for(j=1;j<=n+1;j++)scanf("%lf",&G[i][j]);
29     }
30     for(i=1;i<n;i++)guess(i);
31     for(i=n;i>=1;i--)res[i]=r_guess(i);
32     for(i=1;i<=n;i++)printf("%d ",(int)floor(res[i]+0.5));
33     return 0;
34 }