652A - Gabriel and Caterpillar 20171128
按题意模拟即可
#include<stdlib.h> #include<stdio.h> #include<math.h> #include<cstring> #include<iostream> #include<algorithm> using namespace std; int h1,h2,a,b,ans=1; int main() { scanf("%d%d%d%d",&h1,&h2,&a,&b); if(h1+8*a>=h2)return printf("0\n"),0; if(a<=b)return printf("-1\n"),0; h1+=8*a-12*b; while(true) { if(h1+12*a>=h2)return printf("%d\n",ans),0; h1+=12*(a-b),ans++; } }
652B - z-sort 20171128
排序之后把大的数字放偶数位即可
#include<stdlib.h> #include<stdio.h> #include<math.h> #include<cstring> #include<iostream> #include<algorithm> using namespace std; int n,a[1001],ans[1001]; int main() { scanf("%d",&n);int N=n; for(int i=1;i<=n;i++) scanf("%d",&a[i]); sort(a+1,a+n+1); for(int i=1;i<=n;i+=2)ans[i]=a[i+1>>1]; for(int i=N-(N&1);i>=2;i-=2)ans[i]=a[n--]; for(int i=1;i<=N;i++) printf("%d%c",ans[i],i==N?'\n':' '); return 0; }
652C - Foe Pairs 20171128
对每个数记录所有和他组成Foe Pair的数字位置即可
#include<stdlib.h> #include<stdio.h> #include<math.h> #define N 300001 #include<vector> #include<cstring> #include<iostream> #include<algorithm> using namespace std; #define LL long long #define MOD 1000000007 LL n,m,a,b,ans,p[N],pos[N]; vector<LL>f[N]; int main() { scanf("%I64d%I64d",&n,&m); for(LL i=1;i<=n;i++) scanf("%I64d",&p[i]),pos[p[i]]=i; for(LL i=1;i<=m;i++) { scanf("%I64d%I64d",&a,&b); if(pos[a]>pos[b]) swap(a,b); f[pos[a]].push_back(pos[b]-1); } LL _=n; for(LL i=n;i>=1;i--) { for(LL j=0;j<f[i].size();j++) _=min(_,f[i][j]); ans+=_-i+1; } printf("%I64d\n",ans); return 0; }
652D - Nested Segments 20190312
离散化后用树状数组处理即可
#include<bits/stdc++.h> using namespace std; #define N 200001 int n,l[N],r[N],a[N],f[N],t[N]; map<int,int>mp; int lowbit(int x){return x&(-x);} bool cmpl(int x,int y){return l[x]<l[y];} bool cmpr(int x,int y){return r[x]<r[y];} void change(int x,int c){while(x<N)t[x]+=c,x+=lowbit(x);} int ask(int x){int res=0;while(x)res+=t[x],x-=lowbit(x);return res;} int main() { scanf("%d",&n); for(int i=1;i<=n;i++) scanf("%d%d",&l[i],&r[i]),a[i]=i; sort(a+1,a+n+1,cmpr); for(int i=1;i<=n;i++) mp[r[a[i]]]=i; sort(a+1,a+n+1,cmpl); for(int i=1;i<=n;i++) change(i,1); for(int i=1;i<=n;i++) change(mp[r[a[i]]],-1),f[a[i]]=ask(mp[r[a[i]]]); for(int i=1;i<=n;i++)printf("%d\n",f[i]); }
652E - Pursuit For Artifacts 20190402
缩点后深搜一次即可，注意细节处理
#include<bits/stdc++.h> using namespace std; #define N 300001 #define mp make_pair stack<int>s,t; vector<pair<int,int> >d[N],d2[N]; int n,m,u,v,z,cnt,dcnt,f[N],dfn[N],low[N],flg[N]; void dfs(int cur,int pre) { s.push(cur); low[cur]=dfn[cur]=++dcnt; for(auto nxt:d[cur])if(nxt.first!=pre) { if(!dfn[nxt.first])dfs(nxt.first,cur); low[cur]=min(low[cur],low[nxt.first]); } if(dfn[cur]==low[cur]) { cnt++; while(s.top()!=cur) f[s.top()]=cnt,t.push(s.top()),s.pop(); f[s.top()]=cnt,t.push(s.top()),s.pop(); while(!t.empty()) { int x=t.top();t.pop(); for(auto y:d[x]) if(f[x]==f[y.first]) flg[cnt]|=y.second; } } } void dfs2(int cur,int pre) { flg[cur]|=flg[pre]; for(auto nxt:d2[cur]) if(nxt.first!=pre) flg[nxt.first]|=nxt.second, dfs2(nxt.first,cur); } int main() { scanf("%d%d",&n,&m); for(int i=1;i<=m;i++) { scanf("%d%d%d",&u,&v,&z); d[u].push_back(mp(v,z)); d[v].push_back(mp(u,z)); } for(int i=1;i<=n;i++) sort(d[i].begin(),d[i].end()); for(int i=1;i<=n;i++) if(!dfn[i])dfs(i,0); for(int i=1;i<=n;i++) for(auto j:d[i])if(f[i]!=f[j.first]) d2[f[i]].push_back(mp(f[j.first],j.second)); scanf("%d%d",&u,&v); dfs2(f[u],0); printf("%s\n",flg[f[v]]?"YES":"NO"); return 0; }
652F - Ants on a Circle 20190403