BZOJ3112 ZJOI2013 防守战线

【待填

 

Code:

  #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <queue>

#define ps system("pause")
#define message printf("*\n")
#define pb push_back
#define X first	
#define Y second
#define PII pair<int,int>
#define rep(a,b,c) for(int a=b;a<=c;a++)
#define per(a,b,c) for(int a=b;a>=c;a--)

using namespace std;

int n,m;
int info[10010][10010];
int pb[10010];

void init(){
	scanf("%d%d",&n,&m);
	rep(i,1,n)	scanf("%d",&info[i][0]);
	rep(i,1,m){
		int l,r,qk;
		scanf("%d%d%d",&l,&r,&qk);
		rep(j,l,r)	info[j][i]=1;
		info[0][i]=qk;
	}
}

void pivot(int x,int ned){
	pb[0]=1;pb[1]=0;
	rep(i,1,m)	if	(info[x][i])	pb[++pb[0]]=i;
	rep(i,0,n){
		if	(info[i][ned]==0	||	i==x)	continue;
		rep(j,1,pb[0])	if	(pb[j]!=ned)
			info[i][pb[j]]-=info[i][ned]*info[x][pb[j]];
		info[i][ned]=-info[i][ned];
	}
}

void work(){
	while	(1){
		int now=-1;
		rep(i,1,m)	if	(info[0][i]>0)	{now=i;break;}
		if	(now<0)	return	;
		int mx=0x7fffffff,po;
		rep(i,1,n)
			if	(info[i][now]>0 && info[i][0]<mx){
				mx=info[i][0];po=i;
			}
		pivot(po,now);
	}
}

int main(){
	init();
	work();
	printf("%d\n",-info[0][0]);
}