Solution of HihoCoder 1015: KMP

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cstring>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <algorithm>
#include <functional>
#include <iomanip>
using namespace std;

#define LL long long
const int maxn = 1000000 + 100;
int T;
int Next[maxn];
char str1[maxn], str2[maxn];

void get_next(char *str) {
    int j = 0;
    for(int i = 2; str[i]; ++i) {
        while(j != 0 && str[i] != str[j + 1]) {
            j = Next[j];
        }
        if(str[i] == str[j + 1]) {
            ++j;
        }
        Next[i] = j;
    }
}

int kmp(char *str1, char *str2) {
    int j = 0;
    int ret = 0;
    for(int i = 1; str1[i]; ++i) {
        while(j != 0 && str1[i] != str2[j + 1]) {
            j = Next[j];
        }
        if(str1[i] == str2[j + 1]) {
            ++j;
        }
        if(str2[j + 1] == '\0') {
            j = Next[j];
            ++ret;
        }
    }
    return ret;
}

int main() {
    #ifdef LOCAL
    freopen("test.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);
    #endif // LOCAL
    ios::sync_with_stdio(false);

    scanf("%d", &T);
    while(T--) {
        scanf("%s%s", str1 + 1, str2 + 1);
        get_next(str1);
        printf("%d\n", kmp(str2, str1));
    }

    return 0;
}