HDU 4928 Series 2

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神奇的剪枝
将数列中的前导零与后置零去掉
#include<cstdio>#include<cmath>#include<algorithm>#include<iostream>#include<cstring>#include<climits>#include<cstdlib>#include<map>#define pi acos(-1.0)#define eps 1e-8#define ll long long#define L 1000050#define N 100050#define Mod 1000000007#define M 99999999999#define clr(a) memset(a,0,sizeof(a))#pragma comment(linker, "/STACK:102400000,102400000")using namespace std;template<class T>inline bool read(T &n){    T x = 0, tmp = 1;    char c = getchar();    while((c < '0' || c > '9') && c != '-' && c != EOF) c = getchar();    if(c == EOF) return false;    if(c == '-') c = getchar(), tmp = -1;    while(c >= '0' && c <= '9') x *= 10, x += (c - '0'),c = getchar();    n = x*tmp;    return true;}template <class T>inline void write(T n){    if(n < 0)    {        putchar('-');        n = -n;    }    int len = 0,data[20];    while(n)    {        data[len++] = n%10;        n /= 10;    }    if(!len) data[len++] = 0;    while(len--) putchar(data[len]+48);}long long a[N];int main(){    int i,j,k,n;    int cas=1;    int t,sig1,sig2,l,r;    read(T);    while(T--)    {        read(n);        for(i=0;i<n;i++)            read(a[i]);        l=0;        r=n-1;        for(i=0;i<n-1;i++)        {            while(l<r&&!a[l])   l++;            if(l<1)                l=0;            else                l=l-1;            while(r>l&&!a[r])   r--;            if(r+1>n-i-1)                r=n-i-1;            else                r=r+1;            if(l>=r)                break;            sig1=sig2=1;            for(j=l;j<r;j++)            {                if(a[j+1]<a[j])                    sig1=0;                else if(a[j+1]>a[j])                    sig2=0;            }            if(!sig1&&!sig2)            {                if(i==0)                    printf("ugly series\n");                else                    printf("%d\n",i-1);                break;            }            for(j=l;j<r;j++)                a[j]=a[j+1]-a[j];            r--;        }        if(sig1||sig2)            printf("nice series\n");    }    //printf("Case #%d: %d\n",cas++,res);    return 0;}
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