zoj 2770

#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

const int MAXN = 1010;
const int MAXM = 23000;
const int INF = 100000000;

struct Edge
{
int u, v, w;
}edges[MAXM];

int n;
int EN;
int dist[MAXN];
int S[MAXN];

void Inite()
{
EN = 0;
for(int i = 0; i < n; ++i)
{
dist[i] = INF;
}
S[0] = 0;
S
= 0;
}

bool Bellman_Ford()
{
int i, j;
for(i = 0; i < n; ++i)
{
for(j = 0; j < EN; ++j)
if(dist[ edges[j].u ] < INF && dist[ edges[j].u ] + edges[j].w < dist[ edges[j].v ])
dist[ edges[j].v ] = dist[edges[j].u] + edges[j].w;
}

for(j = 0; j < EN; ++j)
if(dist[ edges[j].u ] < INF && dist[ edges[j].u ] + edges[j].w < dist[ edges[j].v ])
return false;

return true;
}

int main()
{
int i;
int m;
int C[MAXN];
int u, v, w;
while(~scanf("%d %d", &n, &m))
{
Inite();
memset(C, 0, sizeof(C));

for(i = 1; i <= n; ++i)
{
cin>>C[i];
edges[EN].u = i-1;
edges[EN].v = i;
edges[EN++].w = C[i];

edges[EN].u = i;
edges[EN].v = i-1;
edges[EN++].w = 0;
S[i] = S[i-1] + C[i];
}

for(i = 0; i < m; ++i)
{
cin>>u>>v>>w;
edges[EN].u = v;
edges[EN].v = u - 1;
edges[EN++].w = -w;

edges[EN].u = u-1;
edges[EN].v = v;
edges[EN++].w = S[v] - S[u-1];
}

if(!Bellman_Ford())
cout<<"Bad Estimations"<<endl;
else
cout<<dist
- dist[0]<<endl;
}
}