单纯形模板

来源：互联网发布：js正则表达式可以为空编辑：程序博客网时间：2024/06/01 09:48
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#include <cstdio>#include <cstring>#include <algorithm>#define fo(i,a,b) for(int i=a;i<=b;i++)using namespace std;typedef long double db;const int N=25;db a[N][N],eps=1e-9;int id[N*2],n,m,t,x;double ans[N*2];bool pd;db abs(db x) {return x<0?-x:x;}void pivot(int l,int e) {    swap(id[n+l],id[e]);    db t=a[l][e];a[l][e]=1;    fo(i,0,n) a[l][i]/=t;    fo(i,0,m)         if (i!=l&&abs(a[i][e])>eps) {            db t=a[i][e];a[i][e]=0;            fo(j,0,n) a[i][j]-=t*a[l][j];        }}void prepare() {    while (1) {        int l=0,e=0;        fo(i,1,m) if (a[i][0]<-eps&&(!l||(rand()&1))) l=i;        if (!l) break;        fo(i,1,n) if (a[l][i]<-eps&&(!e||(rand()&1))) e=i;        if (!e) {pd=1;return;}        pivot(l,e);    }}void solve() {    while (1) {        int l=0,e=0;db mn=1e18;        fo(i,1,n) if (a[0][i]>eps) {e=i;break;}        if (!e) break;        fo(i,1,m)            if (a[i][e]>eps&&a[i][0]/a[i][e]<mn) {                mn=a[i][0]/a[i][e];                l=i;            }        if (!l) {pd=1;return;}        pivot(l,e);    }}int main() {    srand(233);    scanf("%d%d%d",&n,&m,&t);    fo(i,1,n) scanf("%d",&x),a[0][i]=x;    fo(i,1,m) {        fo(j,1,n) scanf("%d",&x),a[i][j]=x;        scanf("%d",&x);a[i][0]=x;    }    fo(i,1,n+m) id[i]=i;     prepare();    if (pd) {        printf("Infeasible\n");        return 0;    }    pd=0;    solve();    if (pd) {        printf("Unbounded\n");        return 0;    }    printf("%.15lf\n",-(double)a[0][0]);    if (t) {        fo(i,1,m) ans[id[i+n]]=a[i][0];        fo(i,1,n) printf("%.15lf ",ans[i]);    }}
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