这道题来得更加赤裸裸.，连题目都这么赤裸裸，纯属熟悉代码
code
#include <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <stack>
#include <limits>
#include <vector>
#include <bitset>
#include <string>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <string.h>
#include <iostream>
#include <algorithm>
#define Si set<int>
#define LL long long
#define pb push_back
#define PS printf(" ")
#define Vi vector<int>
#define LN printf("\n")
#define lson l,m,rt << 1
#define rson m+1,r,rt<<1|1
#define SD(a) scanf("%d",&a)
#define PD(a) printf("%d",a)
#define SET(a,b) memset(a,b,sizeof(a))
#define FF(i,a) for(int i(0);i<(a);i++)
#define FD(i,a) for(int i(a);i>=(1);i--)
#define FOR(i,a,b) for(int i(a);i<=(b);i++)
#define FOD(i,a,b) for(int i(a);i>=(b);i--)
#define readf freopen("input.txt","r",stdin)
#define writef freopen("output.txt","w",stdout)
const int maxn = 205;
const int INF = 0xfffffff;
const int dx[]={0,1,0,-1};
const int dy[]={1,0,-1,0};
const double pi = acos(-1.0);
using namespace std;
int dis[maxn],edge[maxn][maxn];
bool vis[maxn];
int main()
{
int N,M,a,b,x,tmp,k;
while(~scanf("%d%d",&N,&M)&& (N || M)){
FOR(i,1,N) FOR(j,1,N) edge[i][j]=INF;
SET(vis,false);
FOR(i,1,N) dis[i]=INF;
FOR(i,1,M){
scanf("%d%d%d",&a,&b,&x);
edge[a][b]=edge[b][a]=min(edge[a][b],x);
}
FOR(i,2,N){
dis[i]=edge[1][i];
}
//dijstra
vis[1]=true;
dis[1]=0;
FOR(i,2,N){
tmp=INF;
FOR(j,1,N){
if(!vis[j] && dis[j]<tmp){
tmp=dis[j];
k=j;
}
}
if(k==N) break;
vis[k]=true;
FOR(j,1,N){
if(!vis[j] && dis[j] > dis[k]+edge[k][j])
dis[j]=dis[k]+edge[k][j];
}
}
printf("%d\n",dis[N]);
}
return 0;
}
下面是链式前向星存储
code
/*
ID : Your ID
LANG : C++
PROB : namenum
*/
#include <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <stack>
#include <limits>
#include <vector>
#include <bitset>
#include <string>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <string.h>
#include <iostream>
#include <algorithm>
#define Si set<int>
#define LL long long
#define pb push_back
#define PS printf(" ")
#define Vi vector<int>
#define LN printf("\n")
#define lson l,m,rt << 1
#define rson m+1,r,rt<<1|1
#define SD(a) scanf("%d",&a)
#define PD(a) printf("%d",a)
#define SET(a,b) memset(a,b,sizeof(a))
#define FF(i,a) for(int i(0);i<(a);i++)
#define FD(i,a) for(int i(a);i>=(1);i--)
#define FOR(i,a,b) for(int i(a);i<=(b);i++)
#define FOD(i,a,b) for(int i(a);i>=(b);i--)
#define readf freopen("input.txt","r",stdin)
#define writef freopen("output.txt","w",stdout)
const int maxn = 1005;
const int INF = 0x3fffffff;
const int dx[]={0,1,0,-1};
const int dy[]={1,0,-1,0};
const double pi = acos(-1.0);
using namespace std;
int N,M;// vertex num , edge num;
struct Edge{
int v, next, w;
}Graph[maxn*maxn];
int e_cnt, adj[maxn*2], dis[maxn], vis[maxn];
void add_E(int u, int v, int w){
Graph[e_cnt].v=v;
Graph[e_cnt].w=w;
Graph[e_cnt].next=adj[u];
adj[u]=e_cnt++;
Graph[e_cnt].v=u;
Graph[e_cnt].w=w;
Graph[e_cnt].next=adj[v];
adj[v]=e_cnt++;
}
void dijstra(){
SET(vis,false);
FOR(i,1,N) dis[i]=INF;
dis[1]=0;
int tmp,k;
FOR(i,1,N){
tmp=INF;
FOR(j,1,N){
if(!vis[j] && dis[j]<tmp){
k=j;
tmp=dis[j];
}
}
if(tmp== INF || k==N) break;
vis[k]=true;
// 松弛
for(int j=adj[k];j;j=Graph[j].next){
int w=Graph[j].w;
int v=Graph[j].v;
if( dis[v] > tmp+w ) dis[v]=tmp+w;
}
}
PD(dis[N]);LN;
}
void print(int u){
for(int i=adj[u]; i;i=Graph[i].next){
printf("%d-->%d the w: %d \n",u,Graph[i].v,Graph[i].w);
}
return ;
}
int main()
{
while(~scanf("%d%d",&N,&M) && (N || M)){
SET(adj,0);
e_cnt=1;
int A,B,C;
FOR(i,1,M){
scanf("%d%d%d",&A,&B,&C);
add_E(A,B,C);
}
// FOR(i,1,N){
// print(i);LN;
// }
dijstra();
}
return 0;
}
下面这个代码是 链式前向星+spfa
/*
ID : Your ID
LANG : C++
PROB : namenum
*/
#include <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <stack>
#include <limits>
#include <vector>
#include <bitset>
#include <string>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <string.h>
#include <iostream>
#include <algorithm>
#define Si set<int>
#define LL long long
#define pb push_back
#define PS printf(" ")
#define Vi vector<int>
#define LN printf("\n")
#define lson l,m,rt << 1
#define rson m+1,r,rt<<1|1
#define SD(a) scanf("%d",&a)
#define PD(a) printf("%d",a)
#define SET(a,b) memset(a,b,sizeof(a))
#define FF(i,a) for(int i(0);i<(a);i++)
#define FD(i,a) for(int i(a);i>=(1);i--)
#define FOR(i,a,b) for(int i(a);i<=(b);i++)
#define FOD(i,a,b) for(int i(a);i>=(b);i--)
#define readf freopen("input.txt","r",stdin)
#define writef freopen("output.txt","w",stdout)
const int maxn = 1005;
const int INF = 0x3fffffff;
const int dx[]={0,1,0,-1};
const int dy[]={1,0,-1,0};
const double pi = acos(-1.0);
using namespace std;
int N,M;// vertex num , edge num;
struct Edge{
int v, next, w;
}Graph[maxn*maxn];
int e_cnt, adj[maxn], dis[maxn], vis[maxn];
queue<int> q;
void add_E(int u, int v, int w){
Graph[e_cnt].v=v;
Graph[e_cnt].w=w;
Graph[e_cnt].next=adj[u];
adj[u]=e_cnt++;
Graph[e_cnt].v=u;
Graph[e_cnt].w=w;
Graph[e_cnt].next=adj[v];
adj[v]=e_cnt++;
}
void print(int u){
for(int i=adj[u]; i;i=Graph[i].next){
printf("%d-->%d the w: %d \n",u,Graph[i].v,Graph[i].w);
}
return ;
}
void spfa(){
while (!q.empty())
{
q.pop();
}
SET(vis,false);
FOR(i,1,N) dis[i]=INF;
dis[1]=0;
vis[1]=true;
q.push(1);
while(!q.empty()){
int tmp=q.front();
q.pop();
vis[tmp]=false;
for(int j=adj[tmp];j;j=Graph[j].next){
int w=Graph[j].w;
if( w+ dis[tmp] < dis[Graph[j].v]){
dis[Graph[j].v]=w+ dis[tmp];
if (!vis[Graph[j].v])
{
vis[Graph[j].v]=true;
q.push(Graph[j].v);
}
}
}
}
PD(dis[N]);LN;
}
int main()
{
while(~scanf("%d%d",&N,&M) && (N || M)){
SET(adj,0);
e_cnt=1;
int A,B,C;
FOR(i,1,M){
scanf("%d%d%d",&A,&B,&C);
add_E(A,B,C);
}
spfa();
}
return 0;
}