Submission #1401362

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Source Code Expand

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define GG return puts("No"),0;
const int maxn=100005;
typedef long long ll;
int ufs1[maxn];ll w1[maxn];
int ufs2[maxn];ll w2[maxn];
struct node{
  int x,y,val;
  void read(){
    scanf("%d%d%d",&x,&y,&val);
  }
}P[maxn];
bool cmpx(const node &A,const node &B){
  return A.x<B.x;
}
bool cmpy(const node &A,const node &B){
  return A.y<B.y;
}
int find1(int x){
  if(x==ufs1[x])return x;
  int rt=find1(ufs1[x]);
  w1[x]+=w1[ufs1[x]];
  return ufs1[x]=rt;
}
int find2(int x){
  if(x==ufs2[x])return x;
  int rt=find2(ufs2[x]);
  w2[x]+=w2[ufs2[x]];
  return ufs2[x]=rt;
}
bool link1(int a,int b,ll w){
  if(find1(a)!=find1(b)){
    int ra=find1(a),rb=find1(b);
    ufs1[ra]=ufs1[rb];
    w1[ra]=w+w1[b]-w1[a];
    return true;
  }else{
    return w1[a]==w+w1[b];
  }
}
bool link2(int a,int b,ll w){
  if(find2(a)!=find2(b)){
    int ra=find2(a),rb=find2(b);
    ufs2[ra]=ufs2[rb];
    w2[ra]=w+w2[b]-w2[a];
    return true;
  }else{
    return w2[a]==w+w2[b];
  }
}
ll Min1[maxn],Min2[maxn];
int main(){
  int R,C;scanf("%d%d",&R,&C);
  for(int i=1;i<=R;++i){
    ufs1[i]=i;w1[i]=0;
  }
  for(int i=1;i<=C;++i){
    ufs2[i]=i;w2[i]=0;
  }
  int n;scanf("%d",&n);
  for(int i=1;i<=n;++i)P[i].read();
  sort(P+1,P+n+1,cmpx);
  for(int i=1;i<n;++i){
    if(P[i].x==P[i+1].x){
      if(!link2(P[i].y,P[i+1].y,P[i+1].val-P[i].val))GG;
    }
  }
  sort(P+1,P+n+1,cmpy);
  for(int i=1;i<n;++i){
    if(P[i].y==P[i+1].y){
      if(!link1(P[i].x,P[i+1].x,P[i+1].val-P[i].val))GG;
    }
  }
  memset(Min1,0x3f,sizeof(Min1));
  memset(Min2,0x3f,sizeof(Min2));
  for(int i=1;i<=n;++i){
    int rt=find1(P[i].x);
    Min1[rt]=min(Min1[rt],P[i].val+w1[P[i].x]);
  }
  for(int i=1;i<=R;++i){
    int rt=find1(i);
    Min2[rt]=min(Min2[rt],-w1[i]);
  }
  for(int i=1;i<=R;++i){
    if(ufs1[i]==i&&Min1[i]+Min2[i]<0){
      GG;
    }
  }
  memset(Min1,0x3f,sizeof(Min1));
  memset(Min2,0x3f,sizeof(Min2));
  for(int i=1;i<=n;++i){
    int rt=find2(P[i].y);
    Min1[rt]=min(Min1[rt],P[i].val+w2[P[i].y]);
  }
  for(int i=1;i<=C;++i){
    int rt=find2(i);
    Min2[rt]=min(Min2[rt],-w2[i]);
  }
  for(int i=1;i<=C;++i){
    if(ufs2[i]==i&&Min1[i]+Min2[i]<0)GG;
  }
  printf("Yes\n");
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:56:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   int R,C;scanf("%d%d",&R,&C);
                              ^
./Main.cpp:63:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   int n;scanf("%d",&n);
                       ^
./Main.cpp: In member function ‘void node::read()’:
./Main.cpp:13:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d",&x,&y,&val);
                               ^

Judge Result