如果北京到上海有千亿条路，寻找最短路径用C语言编程用枚举法没效率，应该用什么算法才能高效解决它？

迪杰斯特拉（Dijkstra）算法求图的单源最短路径
template<class Type>
void Dijkstra(int n, int v, Type dist[], int prev[], Type **c) {
//单源最短路径问题的 Dijkstra 算法
bool s[maxint];
for (int i = 1; i <= n; i++) {
dist[i] = c[v][i];
s[i] = false;
if (dist[i] == maxint) prev[i] = 0;
else prev[i] = v;
}
dist[v] = 0; s[v] = true;
for (int i = 1; i < n; i++) {
int temp = maxint;
int u = v;
for (int j = 1; j <= n; j++)
if (!s[j] && dist[j] < temp) {
u = j;
temp = dist[j];
}
s[u] = true;
for (int j = 1; j <= n; j++)
if (!s[j] && c[i][j] < maxint) {
Type newdist = dist[u] + c[u][j];
if (newdist < dist[j]) {
dist[j] = newint;
prev[j] = u;
}
}
}
}