UVA10498 Happiness 【单纯形】

题目链接

UVA10498

题解

模板题

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<vector>

#include<queue>

#include<cmath>

#include<map>

#define LL long long int

#define REP(i,n) for (int i = 1; i <= (n); i++)

#define Redge(u) for (int k = h[u],to; k; k = ed[k].nxt)

#define cls(s,v) memset(s,v,sizeof(s))

#define mp(a,b) make_pair<int,int>(a,b)

#define cp pair<int,int>

using namespace std;

const int maxn = 25,maxm = 100005;

const double eps = 1e-12,INF = 1e15;

int n,m;

double a[maxn][maxn];

void Pivot(int l,int e){

	double t = a[l][e]; a[l][e] = 1;

	for (int j = 0; j <= n; j++) a[l][j] /= t;

	for (int i = 0; i <= m; i++) if (l != i && fabs(a[i][e]) > 0){

		t = a[i][e]; a[i][e] = 0;

		for (int j = 0; j <= n; j++) a[i][j] -= a[l][j] * t;

	}

}

void simplex(){

	while (true){

		int l = 0,e = 0; double mn = INF;

		for (int j = 1; j <= n; j++) if (a[0][j] > eps){e = j; break;}

		if (!e) break;

		for (int i = 1; i <= m; i++) if (a[i][e] > eps && a[i][0] / a[i][e] < mn)

			mn = a[i][0] / a[i][e],l = i;

		Pivot(l,e);

	}

}

int main(){

	while (~scanf("%d%d",&n,&m)){

		REP(j,n) scanf("%lf",&a[0][j]);

		REP(i,m){

			REP(j,n) scanf("%lf",&a[i][j]);

			scanf("%lf",&a[i][0]);

		}

		a[0][0] = 0;

		simplex();

		printf("Nasa can spend %lld taka.\n",(LL)floor((-a[0][0]) * m + 1 - eps));

	}

	return 0;

}