洛谷P1001题解合集

题目传送门
传送到题目，你会一脸骄傲：这题也太简单了吧！不就是算A+B吗？
但是，你要注意：

1. $Pascal$使用$integer$会爆掉哦！
2. 有负数哦！
3. $c/c++$的$main$函数必须是$int$类型，而且最后要$return0$。这不仅对洛谷其他题目有效，而且也是$noip/noi$比赛的要求！
   ————————————————————————————————
   代码：
   正常$C++$版：

#include
using namespace std;
int main(){
	int a,b;
	cin>>a>>b;
	cout<<a+b<<endl;
	return 0;
}

丧心病狂函数$1$版：

#include
#include
#include
#include
using namespace std;
struct node 
{
    int data,rev,sum;
    node *son[2],*pre;
    bool judge();
    bool isroot();
    void pushdown();
    void update();
    void setson(node *child,int lr);
}lct[233];
int top,a,b;
node *getnew(int x)
{
    node *now=lct+ ++top;
    now->data=x;
    now->pre=now->son[1]=now->son[0]=lct;
    now->sum=0;
    now->rev=0;
    return now;
}
bool node::judge(){return pre->son[1]==this;}
bool node::isroot()
{
    if(pre==lct)return true;
    return !(pre->son[1]==this||pre->son[0]==this);
}
void node::pushdown()
{
    if(this==lct||!rev)return;
    swap(son[0],son[1]);
    son[0]->rev^=1;
    son[1]->rev^=1;
    rev=0;
}
void node::update(){sum=son[1]->sum+son[0]->sum+data;}
void node::setson(node *child,int lr)
{
    this->pushdown();
    child->pre=this;
    son[lr]=child;
    this->update();
}
void rotate(node *now)
{
    node *father=now->pre,*grandfa=father->pre;
    if(!father->isroot()) grandfa->pushdown();
    father->pushdown();now->pushdown();
    int lr=now->judge();
    father->setson(now->son[lr^1],lr);
    if(father->isroot()) now->pre=grandfa;
    else grandfa->setson(now,father->judge());
    now->setson(father,lr^1);
    father->update();now->update();
    if(grandfa!=lct) grandfa->update();
}
void splay(node *now)
{
    if(now->isroot())return;
    for(;!now->isroot();rotate(now))
    if(!now->pre->isroot())
    now->judge()==now->pre->judge()?rotate(now->pre):rotate(now);
}
node *access(node *now)
{
    node *last=lct;
    for(;now!=lct;last=now,now=now->pre)
    {
        splay(now);
        now->setson(last,1);
    }
    return last;
}
void changeroot(node *now)
{
    access(now)->rev^=1;
    splay(now);
}
void connect(node *x,node *y)
{
    changeroot(x);
    x->pre=y;
    access(x);
}
void cut(node *x,node *y)
{
    changeroot(x);
    access(y);
    splay(x);
    x->pushdown();
    x->son[1]=y->pre=lct;
    x->update();
}
int query(node *x,node *y)
{
    changeroot(x);
    node *now=access(y);
    return now->sum;
}
int main()
{
    scanf("%d%d",&a,&b);
    node *A=getnew(a);
    node *B=getnew(b);
    //连边 Link
        connect(A,B);
    //断边 Cut
        cut(A,B);
    //再连边orz Link again
        connect(A,B);
    printf("%d\n",query(A,B)); 
    return 0;
}

丧心病狂函数$2$版：

#include
#include
using namespace std;
int lowbit(int a)
{
    return a&(-a);
}
int main()
{
    int n=2,m=1;
    int ans[m+1];
    int a[n+1],c[n+1],s[n+1];
    int o=0;
    memset(c,0,sizeof(c));
    s[0]=0;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        s[i]=s[i-1]+a[i];
        c[i]=s[i]-s[i-lowbit(i)];//树状数组创建前缀和优化
    }
    for(int i=1;i<=m;i++)
    {
        int q=2;
        //if(q==1)
        //{（没有更改操作）
        //    int x,y;
        //    cin>>x>>y;
        //    int j=x;
        //    while(j<=n)
        //    {
        //        c[j]+=y;
        //        j+=lowbit(j);
        //    }
        //}
        //else
        {
            int x=1,y=2;//求a[1]+a[2]的和
            int s1=0,s2=0,p=x-1;
            while(p>0)
            {
                s1+=c[p];
                p-=lowbit(p);//树状数组求和操作，用两个前缀和相减得到区间和
            }
            p=y;
            while(p>0)
            {
                s2+=c[p];
                p-=lowbit(p);
            }    
            o++;
            ans[o]=s2-s1;//存储答案
        }
    }
    for(int i=1;i<=o;i++)
        cout<<ans[i]<<endl;//输出
    return 0;
}

Pascal版：

var
	a,b,c:longint;
begin
	read(a);
	read(b);
	c:=a+b;
	writeln(c);
end.

Scala版:

import scala.io._
object Test
{
    def main(args: Array[String])
    {
        val a = StdIn.readInt()
        val b = StdIn.readInt()
        println(a+b)
    }
}

此文章完。