HDU 2544 shortest and hdu2544 shortest

HDU 2544 shortest and hdu2544 shortest

Link: Http://acm.hdu.edu.cn/showproblem.php? Pid = 1, 2544

Analysis:

First, the data volume is V <= 100

So no basic short-circuit algorithm will time out!

Common Data:

5 6 1 2 10 1 3 4 2 2 3 3 3 2 5 5 4 5 100 // Answer: 14 2 4 1 2 10 1 3 4 2 2 3 4 3 // Answer: 9

Bellman-Ford Algorithm:

#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <iostream>#include <cstring>#include <string>#include <vector>#include <queue>using namespace std;#define MAX_E 10010#define MAX_V 105#define INF 1e8struct edge{int from, to, cost; };edge es[2*MAX_E];int d[MAX_V];int V, E;void shortest_path(int s){    for(int i=1; i<=V; ++i) d[i] = INF;    d[s] = 0;    while(true){        bool update = false;        for(int i=0; i<2*E; ++i){            edge e = es[i];            if(d[e.from] != INF&&d[e.to]>d[e.from]+e.cost){                d[e.to] = d[e.from] + e.cost;                update = true;            }        }        if(!update) break;    }}int main(){    while(~scanf("%d%d", &V, &E), V||E){        int i;        int a,b,c;        for(i=0; i<E; ++i){            scanf("%d%d%d", &a, &b, &c);            es[i].from = a; es[i].to = b; es[i].cost = c;            es[i+E].from = b; es[i+E].to = a; es[i+E].cost = c;        }        shortest_path(1);        printf("%d\n", d[V]);    }}

Dijkstra Algorithm:

#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <iostream>#include <cstring>#include <string>using namespace std;#define MAX_V 105#define MAX_X 105#define INF 1e8int cost[MAX_V][MAX_V];int d[MAX_X];bool used[MAX_X];int n,m;void dijkstra(int s){    for(int i=1; i<=n; ++i){        d[i] = INF;        used[i] = false;    }    d[s] = 0;    while(true){        int v = -1;        for(int u=1; u<=n; ++u){            if(!used[u]&&(v==-1||d[u]<d[v])) v = u;        }        if(v == -1) break;        used[v] = true;        for(int u=1; u<=n; ++u){            d[u] = min(d[u], d[v]+cost[v][u]);        }    }}int main(){    while(~scanf("%d%d", &n, &m), m||n){        int i;        int a,b,c;        for(i=1; i<=n; ++i)            for(int j=1; j<=n; ++j)                cost[i][j] = INF;        for(i=0; i<m; ++i){            scanf("%d%d%d", &a, &b, &c);            cost[a][b] = c;            cost[b][a] = c;        }        dijkstra(1);        printf("%d\n", d[n]);    }}

Floyd algorithm:

#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <iostream>#include <cstring>#include <string>#include <vector>#include <queue>using namespace std;#define MAX_V 105#define MAX_X 105#define INF 1e8int d[MAX_V][MAX_V];bool used[MAX_X];int n,m;void floyd(){    for(int k=1; k<=n; ++k){        for(int i=1; i<=n; ++i){            for(int j=1; j<=n; ++j){                d[i][j] = min(d[i][j], d[i][k]+d[k][j]);            }        }    }}int main(){    while(~scanf("%d%d", &n, &m), m||n){        int i;        int a,b,c;        for(i=1; i<=n; ++i)            for(int j=1; j<=n; ++j)                d[i][j] = INF;        for(i=1; i<=n; ++i) d[i][i] = 0;        for(i=0; i<m; ++i){            scanf("%d%d%d", &a, &b, &c);            d[a][b] = c;            d[b][a] = c;        }        floyd();        printf("%d\n", d[1][n]);    }}

Hdu 2544 (dijkstra)

For (I = 1; I <= n; I ++) for (j = 1; j <= m; j ++) // Here it should be n, instead of m if (I = j) map [I] [j] = 0; else map [I] [j] = max;

Hdu 2544 is too short. How can it be wrong? No error is found.

First, the question requires that all data be input at a time and all results be output at a time. Your program inputs a set of data and outputs a set of results.
Second: In the dij function, the first line of code vis [j] = 1; it should be vis [v] = 1;
If I say more, GM will block my answers. You can implement the details yourself!