HDU 2004 - 2020

版权声明： https://blog.csdn.net/weixin_39778570/article/details/82529421

题目集合:http://acm.hdu.edu.cn/listproblem.php?vol=11
2004 等级判断

#include<iostream>
#include<cstdio>

using namespace std;

double a;
int main(){
    while(scanf("%lf", &a)!=EOF){
        if(90<=a&&a<=100){
            printf("A\n");
        }else if(80<=a&&a<=89){
            printf("B\n");  
        }else if(70<=a&&a<=79){
            printf("C\n");
        }else if(60<=a&&a<=69){
            printf("D\n");
        }else if(0<=a&&a<=59){
            printf("E\n");
        }else{
            printf("Score is error!\n");
        }
    }
} 

2005 第几天?

#include<iostream>
#include<cstdio>

#define rep(i,x) for(int i=0; i<x; i++)
#define REP(i,x) for(int i=1; i<=x; i++)
using namespace std;

char p[20];
int a, b, c;

void chuli(char *s){
    int x = 0;
    const char *ptr = s;
    while(*ptr != '/'){
        x = x*10 + *ptr - '0';
        ptr++;
    }
    a = x;
    ptr++;
    //printf("%d\n", x);
    x = 0;
    while(*ptr != '/'){
        x = x*10 + *ptr - '0';
        ptr++;
    }   
    b = x;
    ptr++;
    //printf("%d\n", x);
    x = 0;
    while(*ptr != 0){
        x = x*10 + *ptr - '0';
        ptr++;
    }
    c = x;
    //printf("%d\n", x);
}

void solve(){
    int ans = 0;
    if(a%400==0 || (a%4==0&&a%100!=0)){
        for(int i=1; i<b; i++){
            if(i==2){
                ans += 29;
            }else if(i==1||i==3||i==5||i==7||i==8||i==10||i==12){
                ans += 31;
            }else{
                ans += 30;
            }
        }       
    }else{
        for(int i=1; i<b; i++){
            if(i==2){
                ans += 28;
            }else if(i==1||i==3||i==5||i==7||i==8||i==10||i==12){
                ans += 31;
            }else{
                ans += 30;
            }
        }
    }
    ans += c;
    printf("%d\n", ans);
}

int main(){
    while(scanf("%s", p)!=EOF){
        chuli(p);
        solve();
    }
    return 0;
}

2006 求奇数的乘积

#include<iostream>
#include<cstdio>

#define rep(i,x) for(int i=0; i<x; i++)
#define REP(i,x) for(int i=1; i<=x; i++)
#define LL long long 

using namespace std;

LL n, a, ans=1;
int main(){
    while(scanf("%lld", &n) != EOF){
        ans = 1;
        while(n--){
            scanf("%lld", &a);
            if(a&1){
                ans *= a;
            }
        }
        printf("%lld\n", ans);
    }
}

2007 平方和与立方和

#include<iostream>
#include<cstdio>

#define rep(i,x) for(int i=0; i<x; i++)
#define REP(i,x) for(int i=1; i<=x; i++)
#define LL long long
using namespace std;
int a, b;
LL ans1, ans2;
int main(){
    while(scanf("%d%d", &a, &b) != EOF){
        ans1 = 0;
        ans2 = 0;
        if(a>b) swap(a,b); // 需要交换m,n 
        for(int i=a; i<=b; i++){
            if(i&1){
                ans2 += i*i*i; 
            }else{
                ans1 += i*i;
            }
        }
        printf("%lld %lld\n", ans1, ans2);
    }
    return 0;
}

2008 数值统计

#include<iostream>
#include<cstdio>

#define LL long long 
using namespace std;
int n,ans1, ans2, ans3;
double a;
int main(){
    while(scanf("%d", &n) && n!=0){
        ans1=0,ans2=0,ans3=0;
        for(int i=0; i<n; i++){
            scanf("%lf", &a);
            if(a<0) ans1++;
            else if(a==0) ans2++;
            else ans3++;
        }
        printf("%d %d %d\n", ans1,ans2,ans3);
    }
    return 0;
} 

2009求数列的和

#include<iostream>
#include<cstdio>
#include<algorithm>
#define LL long long
using namespace std;
int n, m;
double ans;
int main(){
    while(scanf("%d%d", &n,&m) != EOF){
        ans = n;
        double t = n;
        for(int i=2; i<=m; i++){
            t = sqrt(t);
            ans += t;   
        }   
        printf("%.2f\n", ans);
    }
    return 0;
}

2010 水仙花数

#include<iostream>
#include<cstdio>
#include<algorithm>

using namespace std;

bool a[1000] = {0}; 
bool ok(int x){
    int t = x;
    int ans = 0;
    ans += pow((x%10),3);
    x /= 10;
    ans += pow((x%10),3);
    x /= 10;
    ans += pow((x%10),3);
    return ans == t;
}
void init(){
    for(int i=100; i<=999; i++){
        if(ok(i)) a[i] = 1;
    }
}
int n, m;
int main(){
    init();
    while(scanf("%d%d", &m, &n)!=EOF){
        int t = 0;
        for(int i=m; i<=n; i++){
            if(a[i]){
                t==0? printf("%d", i) : printf(" %d", i);
                t = 1;
            }
        }
        if(t==0)printf("no\n");
        else printf("\n");
    }

    return 0;
}

2011 多项式求和

#include<iostream>
#include<cstdio>
#include<algorithm>

#define LL long long

using namespace std;

int t, q;
double ans[1001];
void init(){
    double now = 0;
    for(int i=1; i<=1000; i++){
        if(i&1){
            now += 1.0/i;
            ans[i] = now;
        }else{
            now -= 1.0/i;
            ans[i] = now;
        }
    }
}
int main(){
    init();
    scanf("%d", &t);
    while(t--){
        scanf("%d", &q);
        printf("%.2f\n", ans[q]); 
    }
    return 0;
} 

2012 素数判定

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#define LL long long 
#define MAXN 3000

using namespace std;

bool flat[MAXN] = {0};

void init(){
    flat[0] = 1; flat[1] = 1;
    for(int i=2; i<MAXN; i++){
        if(!flat[i]){
            for(int j=i<<1; j<MAXN; j+=i){
                flat[j] = 1;
            }
        }
    }
}
int a, b;
int main(){
    init();
    while(scanf("%d%d",&a,&b)){
        if(a==0 && b==0) break;
        bool f = 0;
        for(int i=a; i<=b; i++){
            int x = i*i+i+41;
            if(flat[x]){
                f = 1;
                printf("Sorry\n");
                break;
            }
        }
        if(!f) printf("OK\n");
    }
    return 0;
}

2013蟠桃记
x为前一天蟠桃数， x - (x/2+1) = now(表示当天蟠桃树) 所以 x/2-1 = now
f[n]/2 - 1 = f[n-1] 故 f[n] = (f[n-1]+1)*2

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>

#define LL long long
using namespace std;

int p[100],s[100];
// 递归 
int PT(int x){
    if(x==1) return p[1] = 1;
    return p[x] = (PT(x-1)+1) * 2;
}
// 递推
void dp(){
    s[1] = 1;
    for(int i=2; i<=32; i++) s[i] = (s[i-1]+1)*2;
} 
int main(){
    //PT(32);
    dp();
    int a;
    while(scanf("%d", &a)!=EOF) printf("%d\n", s[a]);
    return 0;
} 

2014 青年歌手大奖赛_评委会打分

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;

int n;
double a[105];
int main(){
    while(scanf("%d", &n) != EOF){
        for(int i=0; i<n; i++) scanf("%lf", &a[i]);
        sort(a, a+n);
        double sum = 0;
        for(int i=1; i<n-1; i++) sum += a[i];
        printf("%.2f\n", sum/(n-2));
    }
}

2015 偶数求和

#include<iostream>
#include<cstdio>
#include<cstring>
#define LL long long

using namespace std;
int a[101], n, m;
void init(){
    for(int i=1; i<=100; i++){
        a[i] = 2*i;
    }
}

int main(){
    init();
    while(scanf("%d%d", &n,&m)!=EOF){
        int x = 1, f=1;
        int sum = 0, count = 0;
        for(int i=1; i<=n; i++){
            sum += a[i];
            count ++; 
            if(i%m==0){ // m个了 
                if(f) { // 打印开头 
                    printf("%d", sum/m);
                    f = 0;
                }
                else  printf(" %d", sum/m);
                sum = 0;
                count = 0;
            }
        }
        if(sum!=0) printf(" %d", sum/count); // 不足m个 
        f = 1;
        printf("\n");
    }
    return 0;
}

2016 数据的交换输出

#include<iostream>
#include<cstdio>
#include<cstring>
#define LL long long
#define INF 0x3f3f3f3f
using namespace std;
int a[105];
int n;
int main(){
    while(scanf("%d", &n) && n!=0){
        int min = INF;
        int index = -1;
        for(int i=0; i<n; i++){
            scanf("%d", &a[i]);
            if(a[i]<min){
                min = a[i];
                index = i;
            }
        }
        swap(a[0], a[index]);
        for(int i=0; i<n-1; i++) printf("%d ", a[i]);
        printf("%d\n", a[n-1]);
    }
    return 0;
}

2017 字符串统计

#include<iostream>
#include<cstdio>
#include<cstring>

#define LL long long

using namespace std;

char p[1000000];
int main(){
    int t, len, ans;
    scanf("%d", &t);
    while(t--){
        scanf("%s", p);
        len = strlen(p);
        ans=0;
        for(int i=0; i<len; i++){
            if('0'<=p[i] && p[i]<='9'){
                ans++;
            }
        }
        printf("%d\n", ans);
    }

    return 0;
}

2018 母牛的故事
n + n-4 + n-8 + n-12 +… n-4k>=0
菲波拉契数列是是十分有用的，可以用来描述动物的繁衍过程。
f(n) = f(n-1) + f(n-3)
f(n)表示第n年的牛下一年会生牛,
f(n-1)与f(n)是同一头牛，她还会继续生,
f(n-3)表示f(n)那头牛在n-1的时候生的，到了n-3的时候,下一年(第4年)她会生牛
也就是说f(n)等于下一年的自己再加上下一年她生的牛

#include<iostream>
#include<cstdio>
#include<cstring>

#define LL long long

using namespace std;
int dp[105];
int f(int x){
    if(dp[x]!=0)  return dp[x];
    if(x-4<=0)    return dp[x] = x ;
    else          return dp[x] = f(x-1) + f(x-3);
}
int main(){
    dp[1] = 1;
    f(55);
    int n;
    while(scanf("%d",&n) && n!=0){
        printf("%d\n",dp[n]);
    }
    return 0;
}  

2019 数列有序!

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>

#define LL long long 
#define REP(i,n) for(int i=0; i<n; i++)
#define REPP(i,n) for(int i=1; i<=n; i++)
using namespace std;
int n,m, a[200];

int main(){
    while(scanf("%d%d", &n,&m) && (n!=0 || m!=0)){
        REP(i, n) scanf("%d", &a[i]);
        int index = lower_bound(a,a+n,m) - a;
        REP(i, index) printf("%d ",a[i]);
        printf("%d ", m); 
        for(int i=index; i<n-1; i++) printf("%d ", a[i]);
        printf("%d\n", a[n-1]);
    }
} 

2020 绝对值排序

#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define REP(i,n) for(int i=0; i<n; i++)
#define REPP(i,n) for(int i=1; i<=n; i++)
#define P pair<int,int>

bool cmp(P a, P b){
    return a.first>b.first;
}
vector<P> ver;
int main(){
    int n;
    while(scanf("%d", &n) && n!=0){
        ver.clear();
        REP(i, n){
            int a;
            scanf("%d", &a);
            ver.push_back(P(abs(a), a));
        }
        sort(ver.begin(),ver.end(), cmp);
        REP(i,n-1){
            printf("%d ", ver[i].second);
        }
        printf("%d\n",ver[n-1].second);
    }
    return 0;
}