DP算法和dijkstra的代码
时间: 2023-09-03 08:13:27 浏览: 45
DP算法和Dijkstra算法是两个不同的算法,分别用于不同的问题。下面分别给出两个算法的代码实现。
DP算法代码实现(背包问题):
```python
def knapsack(W, wt, val, n):
K = [[0 for x in range(W+1)] for x in range(n+1)]
for i in range(n+1):
for w in range(W+1):
if i==0 or w==0:
K[i][w] = 0
elif wt[i-1] <= w:
K[i][w] = max(val[i-1] + K[i-1][w-wt[i-1]], K[i-1][w])
else:
K[i][w] = K[i-1][w]
return K[n][W]
```
Dijkstra算法代码实现(最短路径问题):
```python
import heapq
def dijkstra(graph, start):
distances = {node: float('inf') for node in graph}
distances[start] = 0
pq = [(0, start)]
while pq:
(dist, current) = heapq.heappop(pq)
if dist > distances[current]:
continue
for neighbor, weight in graph[current].items():
distance = dist + weight
if distance < distances[neighbor]:
distances[neighbor] = distance
heapq.heappush(pq, (distance, neighbor))
return distances
```
这里的代码只是简单的示例,实际使用中需要根据具体问题进行适当的修改。