Submission #143360

#	Time	Username	Problem	Language	Result	Execution time	Memory
143360		nicolaalexandra	Mate (COCI18_mate)	C++14	100 / 100	434 ms	26360 KiB

mate

#include <cstdio>
#include <vector>
#include <set>
#include <cstring>
#define DIM 2010
#define MOD 1000000007
using namespace std;

//ifstream cin ("date.in");
//ofstream cout ("date.out");
int v[DIM],c[DIM][DIM],f[DIM],dp[DIM][30][30],a[DIM][30];
char s[DIM],l1,l2;
int n,i,j,x,y,q,lg;
int main (){

    scanf("%s",s+1);
    n = strlen(s+1);
    for (i=1;i<=n;i++)
        v[i] = s[i] - 'a' + 1;

    c[0][0] = c[1][0] = c[1][1] = 1;
    for (i=2;i<=n;i++){
        c[i][0] = 1;
        for (j=1;j<=i;j++){
            c[i][j] = c[i-1][j] + c[i-1][j-1];
            if (c[i][j] >= MOD)
                c[i][j] -= MOD;
        }}

    /// a[i][x] - in cate moduri pot selecta s[i],j (am nevoie sa stiu pozitia primului)
    for (i=1;i<=n;i++)
        for (j=i+1;j<=n;j++)
            a[i][v[j]]++;

    /// dp[i][x][y] - cate siruri de lungime i care se termina cu xy pot obtine
    for (lg=2;lg<=n;lg++){
        for (i=lg-1;i<=n;i++){
            x = v[i];
            for (y=1;y<=26;y++){
                dp[lg][x][y] = dp[lg][x][y]+1LL*a[i][y]*c[i-1][lg-2]%MOD;
                if (dp[lg][x][y] >= MOD)
                    dp[lg][x][y] -= MOD;
            }}}


    scanf("%d",&q);
    for (;q--;){
        scanf("%d %c %c",&lg,&l1,&l2);
        printf("%d\n",dp[lg][l1-'a'+1][l2-'a'+1]);
    }


    return 0;
}

Compilation message (stderr)

mate.cpp: In function 'int main()':
mate.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s",s+1);
     ~~~~~^~~~~~~~~~
mate.cpp:46:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&q);
     ~~~~~^~~~~~~~~
mate.cpp:48:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %c %c",&lg,&l1,&l2);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100