WA 3 个

#include<bits/stdc++.h>
#define ll long long
using namespace std;
namespace Mashiro {
    char buf[1<<18],*p1=buf,*p2=buf;
    inline int getc() {
        return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<18,stdin),p1==p2)?EOF:*p1++;
    }
    template<typename T>inline void read(T& x) {
        x=0;int f=1;
        char ch=getc();
        while(!isdigit(ch)){if(ch=='-')f=~f+1;ch=getc();}
        while (isdigit (ch)) {x=(x<<3)+(x<<1)+(ch^48);ch=getc();}
        x*=f;
    }      
    template <typename T,typename... Args> inline void read(T& x, Args&... args) {
        read(x);
        read(args...);
    }
    char buffer[1<<18];int p11=-1;const int p22=(1<<18)-1;
    inline void flush() {fwrite(buffer,1,p11+1,stdout),p11=-1;}
    inline void putc(const char &x) {if (p11==p22) flush();buffer[++p11]=x;}
    template<typename T>inline void write(T x) {
        static int buf[40],top=0;
        if(x<0)putc('-'),x=~x+1;
        while(x)buf[++top]=x%10,x/=10;
        if(top==0)buf[++top]=0;
        while (top) putc(buf[top--]^48);
        putc(' ');
        flush();
     }
     template <typename T,typename... Args> inline void write(T x, Args... args) {
         write(x);
         write(args...);
     }
}
using namespace Mashiro;
const int maxn=1000;
const int maxm=1e6+10;
int A,B,ans=0,cnt=0;
namespace UFDS{
    int fa[maxn];
    inline void Memset(int n){
        for(int i(0);i<=n;++i){
            fa[i]=i;
        }
    }
    inline void merge(int u,int v){
        fa[u]=v;
    }
    inline int find(int u){
        if(fa[u]==u)return u;
        else return fa[u]=find(fa[u]);
    }
}
struct node{
    int u,v,w;
}kano[maxm];
int main() {
    read(A,B);
    for(int i(1);i<=B;++i){
        for(int j(1);j<=B;++j){
            ++cnt;
            read(kano[cnt].w);
            if(i>j&&kano[cnt].w<=A&&kano[cnt].w!=0){
                kano[cnt].u=i;
                kano[cnt].v=j;
            }
            else {
                kano[cnt--].w=0;
            }
        }
    }
    for(int i(1);i<=B;++i){
        ++cnt;
        kano[cnt].u=0;
        kano[cnt].v=i;
        kano[cnt].w=A;
    }
    sort(kano+1,kano+1+cnt,[](const node &a,const node &b){
        return a.w<b.w;
    });
    UFDS::Memset(cnt);
    for(int i(1);i<=cnt;++i){
        int u=kano[i].u;
        int v=kano[i].v;
        int fu=UFDS::find(u);
        int fv=UFDS::find(v);
        if(fu==fv)continue;
        UFDS::merge(fu,fv);
        ans+=kano[i].w;
    }
    write(ans);
#ifndef ONLINE_JUDGE
    cout<<endl;
    system("pause");
#endif
    return 0;
}