清北刷题冲刺 11-03 p.m

#include<iostream>
#include<cstdio>
using namespace std;
int n,x,y;
int main(){
    freopen("city.in","r",stdin);freopen("city.out","w",stdout);
//    freopen("Cola.txt","r",stdin);
    scanf("%d",&n);
    while(n--){
        scanf("%d%d",&x,&y);
        int ans=0;
        while(x!=y){
            ans++;
            if(x<y)swap(x,y);
            x/=2;
        }
        printf("%d\n",ans);
    }
    return 0;
}

#include<iostream> 
#include<cstdio>
#include<cstring>
using namespace std;
int n,c,K,mc,cnt[101];
double dp[101][101],ans;
int main(){
    freopen("paint.in","r",stdin);freopen("paint.out","w",stdout);
    scanf("%d%d%d",&n,&c,&K);
    for(int i=1;i<=K;i++){
        int l,r;
        scanf("%d%d",&l,&r);
        for(int j=l;j<=r;j++){
            cnt[j]++;
            mc=max(cnt[j],mc);
        }
    }
    dp[0][1]=1;
    for(int i=0;i<mc;i++){
        for(int j=0;j<c;j++){
            dp[i+1][j]+=dp[i][j]/2;
            for(int k=0;k<c;k++){
                dp[i+1][(j*k)%c]+=dp[i][j]/(2*c);
            }
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=0;j<c;j++){
            ans+=dp[cnt[i]][j]*j;//概率乘以收益
        }
    }
    printf("%.3lf\n",ans);
    return 0;
}

#include<iostream>
#include<cstdio>
#define maxn 21
using namespace std;
int map[21][21],n,m,sum,num,head[maxn],fa[maxn],mx,mn=0x7fffffff;
bool flag=1;
struct node{
    int to,pre,v;
}e[maxn*maxn*2];
void Insert(int from,int to,int v){
    e[++num].to=to;
    e[num].v=v;
    e[num].pre=head[from];
    head[from]=num;
}
void dfs(int now,int father){
    bool leaf=0;
    fa[now]=father;
    for(int i=head[now];i;i=e[i].pre){
        int to=e[i].to;
        if(to==father)continue;
        dfs(to,now);
        leaf=1;
    }
    if(now==n&&leaf==0){
        flag=1;
        return;
    }
}
int main(){
    freopen("vanilla.in","r",stdin);freopen("vanilla.out","w",stdout);
//    freopen("Cola.txt","r",stdin);
    scanf("%d%d",&n,&m);
    int x,y,z;
    for(int i=1;i<=m;i++){
        scanf("%d%d%d",&x,&y,&z);
        mx=max(mx,z);mn=min(mn,z);
        x+=1;y+=1;
        map[x][y]=map[y][x]=z;
        Insert(x,y,z);Insert(y,x,z);
        sum+=z;
        if(x!=i||y!=i+1)flag=0;
    }
    if(flag){
        sum*=4;
        sum-=map[n][n-1]*2+map[1][2]*2;
        cout<<sum;
        return 0;
    }
    if(m==n-1){
        flag=0;
        dfs(1,0);
        if(flag){
            cout<<sum*4-map[n][fa[n]]*2;
        }
        else cout<<sum*4;
        return 0;
    }
    while(sum<177)sum*=2;
    sum%=177;
    if(sum<mx)sum+=mx*2;
    cout<<sum;
    return 0;
}

预计得分100+100+0
实际得分100+50+30
T1很简单，T2是个简单的概率dp，但是数组开小了，T3一点思路都没有，就研究了一下链和树的情况，乱搞了一下
数组开小很不应该们，不能再犯