题目链接1 - - codeforces gym 101873C
题目链接2–codeforces gym 102501A
题目链接3 洛谷 飞行路线
读懂了题之后就是板子题了，一般就是一维的迪杰斯特拉在开一维记录状态
比如 dist[i][j]记录为 到达i点用了j次机会点最短路/权值
或者到达i点路径长度为j的最小花费
Gym 101873C
有个需要注意点地方就是 可以呆在 一个点不动，不是每一步都需要移动
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <vector>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef unsigned long long ull;
const int inf = 0x3f3f3f3f;
const int maxn = 2e5 + 7;
const ll mod = 1000000007;
#define mst(x, a) memset( x,a,sizeof(x) )
#define rep(i, a, b) for(int i=(a);i<=(b);++i)
#define dep(i, a, b) for(int i=(a);i>=(b);--i)
ll read() {
ll x = 0;
char ch = getchar();
while(ch < '0' || ch > '9')ch = getchar();
while(ch >= '0' && ch <= '9')x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
return x;
}
void out(ll x) {
int stackk[40];
if (x < 0) {
putchar('-');
x = -x;
}
if (!x) {
putchar('0');
return;
}
int top = 0;
while (x) stackk[++top] = x % 10, x /= 10;
while (top) putchar(stackk[top--] + '0');
}
int x,n,m,head[maxn],cnt,t,dist[1002][1002],ci;
struct node {
int u,v,w,next,t,p;
} e[maxn];
node c[maxn];
struct Node {
int dian,t,p;
friend bool operator < (const Node &x,const Node &y) {
if(x.p!=y.p)return x.p>y.p;
else return x.t>y.t;
}
Node() {
};
Node(int a,int b,int c) {
dian=a;
t=b;
p=c;
}
};
void add(int u,int v) {
e[cnt].u=u,e[cnt].v=v;
e[cnt].next=head[u],head[u]=cnt++;
}
void D() {
dist[1][c[1].t]=c[1].p;
priority_queue<Node>q;
q.push(Node(1,c[1].t,c[1].p));
while(q.size()) {
ci++;
Node fr= q.top();
q.pop();
int dian=fr.dian;
int ti=fr.t;
if(ci>100000) break;
if(dist[1][x]!=inf) break;
if(dist[dian][ti+c[dian].t]>dist[dian][ti]+c[dian].p) {
dist[dian][ti+c[dian].t]=dist[dian][ti]+c[dian].p;
q.push(Node(dian,ti+c[dian].t,dist[dian][ti+c[dian].t]));
}
for(int i=head[dian]; ~i; i=e[i].next) {
int v=e[i].v;
if(ti+t+c[v].t>x) continue;
if(dist[v][ti+t+c[v].t]>dist[dian][ti]+c[v].p) {
dist[v][ti+t+c[v].t]=dist[dian][ti]+c[v].p;
q.push(Node(v,ti+t+c[v].t,dist[v][ti+t+c[v].t]));
}
}
}
}
int main() {
mst(head,-1);
rep(i,0,1000) rep(j,0,1000) dist[i][j]=inf;
x=read(),n=read(),m=read(),t=read();
for(int i=1 ; i<=m ; i++) {
int u=read();
int v=read();
add(u,v),add(v,u);
}
for(int i=1 ; i<=n ; i++) {
c[i].t=read();
c[i].p=read();
}
D();
if(dist[1][x]>=inf) puts("It is a trap.");
else printf("%d\n",dist[1][x]);
return 0;
}
/**
**/
Gym 102501A
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <vector>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef unsigned long long ull;
const int inf = 0x3f3f3f3f;
const int maxn = 2e5 + 7;
const ll mod = 1000000007;
#define mst(x, a) memset( x,a,sizeof(x) )
#define rep(i, a, b) for(int i=(a);i<=(b);++i)
#define dep(i, a, b) for(int i=(a);i>=(b);--i)
ll read() {
ll x = 0;
char ch = getchar();
while(ch < '0' || ch > '9')ch = getchar();
while(ch >= '0' && ch <= '9')x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
return x;
}
void out(ll x) {
int stackk[40];
if (x < 0) {
putchar('-');
x = -x;
}
if (!x) {
putchar('0');
return;
}
int top = 0;
while (x) stackk[++top] = x % 10, x /= 10;
while (top) putchar(stackk[top--] + '0');
}
int sx,sy,ex,ey,t,c[maxn],n,b;
int head[maxn],cnt,dist[1010][1005],vis[1010][1005];
struct node {
int x,y,u,v,w,next;
} p[maxn];
node e[maxn];
struct Node {
int val,dian,dis;
friend bool operator < (const Node &x,const Node &y) {
if(x.val==y.val) return x.dis>y.dis;
else return x.val>y.val;
}
Node(){
}
Node(int x,int y,int z){
val=x,dian=y,dis=z;
}
};
void add(int u,int v,int w) {
e[cnt].u=u,e[cnt].v=v;
e[cnt].w=w,e[cnt].next=head[u];
head[u]=cnt++;
}
int cal(int id1,int id2) {
int x1=p[id1].x;
int x2=p[id2].x;
int y1=p[id1].y;
int y2=p[id2].y;
int temp=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
return ceil(sqrt(temp));
}
void D() {
priority_queue<Node>q;
dist[0][0]=0;
q.push(Node(0,0,0));
// val dian dis
while(q.size())
{
Node fr=q.top();
q.pop();
int dian=fr.dian;
int dis=fr.dis;
if(vis[dian][dis]) continue;
vis[dian][dis]=1;
for(int i=head[dian];~i;i=e[i].next)
{
int v=e[i].v;
int juli=cal(dian,v);
int pri = juli*c[e[i].w];
if(juli+dis>b) continue;
if(dist[v][juli+dis]>dist[dian][dis]+pri)
{
dist[v][juli+dis]=dist[dian][dis]+pri;
q.push(Node(dist[v][juli+dis],v,juli+dis));
}
}
}
}
int main() {
mst(head,-1);
sx=read(),sy=read(),ex=read(),ey=read(),b=read(),c[0]=read(),t=read();
rep(i,1,t) c[i]=read();
n=read();
rep(i,0,1000) rep(j,0,4000) dist[i][j]=inf;
p[0].x=sx,p[0].y=sy,p[n+1].x=ex,p[n+1].y=ey;
add(0,n+1,0),add(n+1,0,0);
for(int i=1 ; i<=n ; i++) {
int x,y,l;
cin>>x>>y>>l;
p[i].x=x,p[i].y=y;
add(0,i,0),add(n+1,i,0);
add(i,0,0),add(i,n+1,0);
for(int j=1 ; j<=l ; j++) {
int xx,yy;
cin>>xx>>yy;
xx++;
add(i,xx,yy),add(xx,i,yy);
}
}
D();
int ans=inf;
for(int i=0 ;i<=b ;i++) ans=min(ans,dist[n+1][i]);
if(ans==inf) puts("-1");
else printf("%d\n",ans);
return 0;
}
/**
1 1
10 2
12
100
2
10
50
3
2 3 2 1 1 2 2
5 5 1 2 1
9 3 0
**/
洛谷-飞行路线
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <vector>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef unsigned long long ull;
const int inf = 0x3f3f3f3f;
const int maxn = 2e5 + 7;
const ll mod = 1000000007;
#define mst(x, a) memset( x,a,sizeof(x) )
#define rep(i, a, b) for(int i=(a);i<=(b);++i)
#define dep(i, a, b) for(int i=(a);i>=(b);--i)
ll read() {
ll x = 0;
char ch = getchar();
while(ch < '0' || ch > '9')ch = getchar();
while(ch >= '0' && ch <= '9')x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
return x;
}
void out(ll x) {
int stackk[40];
if (x < 0) {
putchar('-');
x = -x;
}
if (!x) {
putchar('0');
return;
}
int top = 0;
while (x) stackk[++top] = x % 10, x /= 10;
while (top) putchar(stackk[top--] + '0');
}
int head[maxn],cnt,n,m,k,st,en,dist[maxn][11];
struct node {
int u,v,w,next;
} e[maxn];
struct Node {
int c,dis,dian;
friend bool operator < (const Node &x,const Node &y) {
return x.dis>y.dis;
}
Node(){
};
Node(int x,int y,int z){
dian=x;
c=y;
dis=z;
}
};
void add(int u,int v,int w) {
e[cnt].u=u,e[cnt].v=v,e[cnt].w=w;
e[cnt].next=head[u],head[u]=cnt++;
}
void D() {
dist[st][0]=0;
priority_queue<Node>q;
q.push(Node(st,0,0));
while(q.size())
{
Node fr = q.top();
q.pop();
int dian=fr.dian;
int c=fr.c;
int dis=fr.dis;
for(int i=head[dian];~i;i=e[i].next)
{
int v=e[i].v;
if(dist[v][c]>dist[dian][c]+e[i].w)
{
dist[v][c]=dist[dian][c]+e[i].w;
q.push(Node(v,c,dist[v][c]));
}
if(dist[v][c+1]>dist[dian][c]&&c+1<=k)
{
dist[v][c+1]=dist[dian][c];
q.push(Node(v,c+1,dist[v][c+1]));
}
}
}
}
int main() {
mst(head,-1);
n=read(),m=read(),k=read();
rep(i,0,n) rep(j,0,10) dist[i][j]=inf;
st=read(),en=read();
st++,en++;
for(int i=1 ; i<=m ; i++) {
int u=read();
int v=read();
int w=read();
u++,v++;
add(u,v,w),add(v,u,w);
}
D();
int ans=inf;
for(int i=0 ;i<=k ;i++) ans=min(ans,dist[en][i]);
out(ans);
return 0;
}
/**
**/