加上快读后：

#include <iostream>
using namespace std;
int xue[5000010];
int c[5000010];
inline int read()
{
	int sum=0,sign=1;
	char ch=getchar();
	if(ch<'0'||ch>'9') 
	{
		if(ch=='-')
		{
			sign=-1;
		    ch=getchar();
		}
	}
	while(ch>='0'&&ch<='9') 
	{
		sum=sum*10+ch-'0'; 
		ch=getchar();
	}
	return sum*sign;
}
void cf(int a,int b,int c1)
{
	c[a]+=c1;
	c[b+1]-=c1;
}
int main() {
	int n,p,minx=100000010;
	cin>>n>>p;
	for (int i=1;i<=n;i++)
	{
	    xue[i]=read();
	}
	for(int i=1;i<=n;i++)
	{
		c[i]=xue[i]-xue[i-1];
	}
	for (int i=1;i<=p;i++)
	{
		int a,b,c;
		a=read();
		b=read();
		c=read();
		cf(a,b,c);
	}
	for (int i=1;i<=n;i++)
	{
	    xue[i]=xue[i-1]+c[i];
		minx=min(minx,xue[i]);
	}
	cout<<minx<<endl;
	return 0;
}