USACO Arithmetic Progressions 【构造等差数列】

USER: Jeremy Wu [wushuai2]

TASK: ariprog

LANG: C++



Compiling...

Compile: OK



Executing...

   Test 1: TEST OK [0.005 secs, 11880 KB]

   Test 2: TEST OK [0.008 secs, 11880 KB]

   Test 3: TEST OK [0.008 secs, 11876 KB]

   Test 4: TEST OK [0.014 secs, 11880 KB]

   Test 5: TEST OK [0.016 secs, 11880 KB]

   Test 6: TEST OK [0.065 secs, 11880 KB]

   Test 7: TEST OK [0.378 secs, 11880 KB]

   Test 8: TEST OK [0.818 secs, 11880 KB]

   Test 9: TEST OK [0.802 secs, 11876 KB]



All tests OK.

Your program ('ariprog') produced all correct answers! This is your submission #5 for this problem. Congratulations!

 

还是算蛮简单的一道构造题目= = 差点以为是要去搜索了...

/*

ID: wushuai2

PROG: ariprog

LANG: C++

*/

//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler

#include <stdio.h>

#include <iostream>

#include <fstream>

#include <cstring>

#include <cmath>

#include <stack>

#include <string>

#include <map>

#include <set>

#include <list>

#include <queue>

#include <vector>

#include <algorithm>

#define Max(a,b) (((a) > (b)) ? (a) : (b))

#define Min(a,b) (((a) < (b)) ? (a) : (b))

#define Abs(x) (((x) > 0) ? (x) : (-(x)))

#define MOD 1000000007

#define pi acos(-1.0)



using namespace std;



typedef long long           ll      ;

typedef unsigned long long  ull     ;

typedef unsigned int        uint    ;

typedef unsigned char       uchar   ;



template<class T> inline void checkmin(T &a,T b){if(a>b) a=b;}

template<class T> inline void checkmax(T &a,T b){if(a<b) a=b;}



const double eps = 1e-7      ;

const int M = 660000         ;

const ll P = 10000000097ll   ;

const int INF = 0x3f3f3f3f   ;

const int MAX_N = 20         ;



int n, m;

bool status[M];

int a[M], len;

int llen;



struct sc{

    int a, b;

}ans[M];



bool cmp(struct sc a, struct sc b){

    if(a.b == b.b)  return a.a < b.a;

    return a.b < b.b;

}



void init(){

    int i, j;

    memset(a, 0, sizeof(a));

    len = 0;

    memset(status, 0, sizeof(status));

    for(i = 0; i <= m; ++i){

        for(j = 0; j <= m; ++j){

            int num = i * i + j * j;

            if(status[num]) continue;

            status[num] = true;

            a[len++] = num;

        }

    }

    a[len] = '\0';

    llen = 0;

}



int main() {

    ofstream fout ("ariprog.out");

    ifstream fin ("ariprog.in");

    int i, j, k, t, s, c, w, q;

    fin >> n >> m;

    init();

    sort(a, a + len);

    for(i = 0; i < len; ++i){

        int num = a[i];

        for(j = 0; j < len; ++j){

            int cur = a[j];     //fisrt a + b

            int b = cur - num;

            if(b * (n - 1) + num > a[len - 1])  break;

            if(b < 1)   continue;

            for(k = 2; k < n; ++k){

                if(!status[num + k * b]){

                    break;

                }

            }

            if(n == k){

                ans[llen].a = num;

                ans[llen++].b = b;

            }

        }



    }





    if(!llen){

        fout << "NONE" << endl;

        return 0;

    }

    sort(ans, ans + llen, cmp);

    for(i = 0; i < llen; ++i){

        cout << ans[i].a << ' ' << ans[i].b << endl;

        fout << ans[i].a << ' ' << ans[i].b << endl;

    }

    fin.close();

    fout.close();

    return 0;

}