no21_1.htm

常用经典算法及讲解：贪婪

yes">&nbsp;&nbsp; </span>gauss(a,f,x,n);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>printf(&quot;the system solution is:\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>for (i=1;i&lt;=n;i++)<span style="mso-spacerun:
yes">&nbsp; </span>printf(&quot;%lf &quot;,x[i]);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>printf(&quot;\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>int inver(double a[20][20],double
e[20][20],int n)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>/* </span><span style='font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>用追赶法求三对角阵</span><span
lang=EN-US> a[][] </span><span style='font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>的逆</span><span
lang=EN-US> */<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>{double ae[20][40],gamma,del;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>int i,j;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>gamma=-a[2][1];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for (i=1;i&lt;=n;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>{for (j=1;j&lt;=n;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>{ ae[i][j]=a[i][j]; ae[i][n+j]=0; }<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>ae[i][n+i]=1;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for(i=1;i&lt;=n-1;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>{if((del=ae[i][i])==0) return 0;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>for (j=i;j&lt;=n*2;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>{ ae[i][j]/=del;
ae[i+1][j]+=ae[i][j]*gamma; }<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>del=ae[n][n];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for(j=n;j&lt;=n*2;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>ae[n][j]/=del;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for(i=1;i&lt;=n;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>{for (j=1;j&lt;=2*n;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>printf(&quot;%8.4f
&quot;,ae[i][j]);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>printf(&quot;\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for(i=n;i&gt;1;i--)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>{ del=ae[i-1][i];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>for (j=i;j&lt;=n*2;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>ae[i-1][j]-=ae[i][j]*del;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for (i=1;i&lt;=n;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>for (j=1;j&lt;=n;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>e[i][j]=ae[i][n+j];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>return 1;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>void mult(double a[][20],double
e[][20],double f[][20],int n)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>{double s;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>int i,j,k;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for (i=1;i&lt;=n;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>for (j=1;j&lt;=n;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>{ s=0;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>for
(k=1;k&lt;=n;k++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span
style="mso-spacerun: yes">&nbsp;</span>s+=a[i][k]*e[k][j];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>if
(fabs(s)&lt;1e-7) s=fabs(s);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>f[i][j]=s;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>void minus(double a[][20],double
b[][20],double c[][20],int n)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>{int i,j;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>for (i=1;i&lt;=n;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>for (j=1;j&lt;=n;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>c[i][j]=a[i][j]-b[i][j];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>main()<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>{<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>int i,j,n,m;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>double
gamma,beta,beta1,a[20][20],b[20][20],c[20][20],d[20][20],<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>e[20][20],f[20][20],deltag,deltax;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>double gx[20]={0,1,0,1,0,-1}, r[20][20],x[20];<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>printf(&quot;</span><span style='font-family:宋体;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"'>请输入主梁数目</span><span
lang=EN-US>,gamma,beta,beta1:\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>scanf(&quot;%d,%lf,%lf,%lf&quot;,&amp;n,&amp;gamma,&amp;beta,&amp;beta1);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>m=n-1;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>for (i=1;i&lt;=m;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>for (j=1;j&lt;=m;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>a[i][j]=b[i][j]=c[i][j]=d[i][j]=0;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>deltag=2*(1+gamma+beta);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>deltax=2*(gamma+3*beta1);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>printf(&quot;%8.4f<span style="mso-spacerun: yes">&nbsp;
</span>%8.4f\n&quot;,deltag,deltax);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>for (i=1;i&lt;=m;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>{ a[i][i]=deltax;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>b[i][i]=deltag;}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>for (i=1;i&lt;=m-1;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun: yes">&nbsp;
</span>{ a[i][i+1]=a[i+1][i]=-gamma;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>b[i][i+1]=b[i+1][i]=gamma-1;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>c[i][i+1]=d[i+1][i]=gamma;<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp; </span>c[i+1][i]=d[i][i+1]=-gamma;}<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>inver(a,e,m);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>for (i=1;i&lt;=m;i++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>{ for (j=1;j&lt;=m;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>printf(&quot;%6.3f &quot;, e[i][j]);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp;&nbsp;&nbsp; </span>printf(&quot;\n&quot;); }<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>mult(c,e,f,m);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>mult(f,d,e,m);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>minus(b,e,r,m);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>gauss(r,gx,x,m);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>printf(&quot;The result is:\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>for (j=1;j&lt;=m;j++)<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;&nbsp; </span>printf(&quot;%8.4f &quot;, x[j]);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US><span style="mso-spacerun:
yes">&nbsp;</span>printf(&quot;\n&quot;);<o:p></o:p></span></p>

<p class=MsoNormal><span lang=EN-US>}<o:p></o:p></span></p>

<p class=MsoNormal></p>

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