Submission #83352

#	Time	Username	Problem	Language	Result	Execution time	Memory
83352		charlies_moo	Mate (COCI18_mate)	C++17	100 / 100	453 ms	36816 KiB

mate

#include <cstdio>
#include <cstring>

const int z = 1e9+7;

int main() {
    char s[2001];
    scanf("%s", s);
    int n = strlen(s);

    int pt[n][n];
    pt[0][0] = 1;
    for (int i = 1; i < n; i++) {
        pt[i][0] = pt[i][i] = 1;
        for (int j = 1; j < i; j++) {
            pt[i][j] = (pt[i-1][j-1] + pt[i-1][j]) % z;
        }
    }

    int c[n][26];
    for (int i = 0; i < 26; i++) {
        c[n-1][i] = 0;
    }
    for (int i = n - 2; i >= 0; i--) {
        for (int j = 0; j < 26; j++) {
            c[i][j] = c[i+1][j];
        }
        c[i][s[i+1]-'a']++;
    }

    int ans[26][26][n];
    memset(ans, 0, sizeof(ans));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < 26; j++) {
            for (int k = 0; k <= i; k++) {
                int t = 1ll * pt[i][k] * c[i][j] % z;
                ans[s[i]-'a'][j][k] = (ans[s[i]-'a'][j][k] + t) % z;
            }
        }
    }

    int q;
    scanf("%d", &q);

    while (q--) {
        int d;
        char xy[3];
        scanf("%d %s", &d, xy);
        printf("%d\n", ans[xy[0]-'a'][xy[1]-'a'][d-2]);
    }

    return 0;
}

Compilation message (stderr)

mate.cpp: In function 'int main()':
mate.cpp:8:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", s);
     ~~~~~^~~~~~~~~
mate.cpp:43:10: 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 %s", &d, xy);
         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100