dijkstra

struct no {
    int v, qtd;
    no() {}
    no(int v, int qtd) : v(v), qtd(qtd) {}
    bool operator < (const no &outro) const {
        return qtd > outro.qtd;
    }
};

vector<int> g[maxn];
int atiradores[maxn];

int dijkstra(int s, int t) {
    int qtd[maxn]; memset(qtd, inf, sizeof qtd);
    priority_queue<no> pq;
    pq.push(no(s, atiradores[s]));
    qtd[s] = atiradores[s];

    while (!pq.empty()) {
        no tmp = pq.top(); pq.pop();
        int u = tmp.v;
        if (u == t) return qtd[u];
        for (int i = 0; i < g[u].size(); i++) {
            int v = g[u][i];
            if (qtd[v] > qtd[u] + atiradores[v]) {
                qtd[v] = qtd[u] + atiradores[v];
                pq.push(no(v, qtd[v]));
            }
        }
    }

    return inf;
}