【图论】【单源最短路】【dijikstra】pascal+邻接矩阵/边集数组

1.邻接矩阵

var  w:array[1..15000,1..15000] of -1..2;    p:array[1..15000] of integer;    i,n,m,t1,t2,t3,t:longint;procedure dijik;var i,j,minn,min:longint;    d:array[1..15000] of longint;    f:array[1..15000] of boolean;begin       fillchar(f,sizeof(f),false);    for i:=1 to n do if w[1,i]<>0 then d[i]:=w[1,i]  else d[i]:=maxlongint;        minn:=1;        f[1]:=true;    d[1]:=0;        for i:=1 to n-2 do begin                min:=maxlongint;                for j:=1 to n do                if (d[j]<min) and (d[j]>0) and (not f[j]) then begin                       minn:=j;                       min:=d[j];                end;        f[minn]:=true;        if min=maxlongint then exit;                for j:=1 to n do if (w[minn,j]<>0) and (not f[j]) then                if (min+w[minn,j]<d[j]) then begin                        d[j]:=min+w[minn,j];                        //p[j]:=minn;                end;        end;        writeln(d[n]);end;begin    readln(n,m);    for i:=1 to m do begin        readln(t1,t2,t3);                w[t1,t2]:=t3;    end;    dijik;end.

2.边集数组

ype     edge = record        a,b:longint;        w:-1..2;    end;var i,n,m:longint;    num:array[0..300001] of longint;    g:array[0..500001] of edge;procedure sort(l,r:longint);var i,j,x,y: longint;begin    i:=l;j:=r;x:=g[(l+r) div 2].a;    repeat        while g[i].a<x do inc(i);        while x<g[j].a do dec(j);            if not(i>j) then begin                    y:=g[i].a;                    g[i].a:=g[j].a;                    g[j].a:=y;            y:=g[i].b;                    g[i].b:=g[j].b;                    g[j].b:=y;            y:=g[i].w;                    g[i].w:=g[j].w;                    g[j].w:=y;                    inc(i);dec(j);                end;         until i>j;         if l<j then sort(l,j);         if i<r then sort(i,r);end;procedure dijik;var i,j,min,minn:longint;    d:array[0..300001] of int64;    f:array[0..300001] of boolean;    pre:array[0..300001] of longint;function find(u,v:longint):longint;var i:longint;begin    find:=0;    for i:=pre[u] to pre[u+1]-1 do with g[i] do if b=v then find:=w;end;begin       for i:=1 to n do d[i]:=maxlongint;    fillchar(f,sizeof(f),false);    sort(1,m);    pre[1]:=1;    for i:=2 to n do pre[i]:=pre[i-1]+num[i-1];    for i:=1 to pre[2]-1 do with g[i] do if w<>0 then d[b]:=w;        minn:=1;f[1]:=true;d[1]:=0;        for i:=1 to n-2 do begin                min:=maxlongint;                for j:=1 to n do                if (d[j]<min) and (not f[j]) then begin                       minn:=j;                       min:=d[j];                end;        if min=maxlongint then exit;        f[minn]:=true;        for j:=1 to n do if not f[j] then begin            t:=find(minn,j);            if (t<>0) and (min+t<d[j]) then d[j]:=min+t;        end;        end;        writeln(d[n]);end;begin    readln(n,m);    for i:=1 to m do with g[i] do readln(a,b,w);    for i:=1 to m do with g[i] do inc(num[a]);     dijik;end.