c++读入比较

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字数统计: 309 个 | 阅读时长 ≈ 2 分

数据: 1e7

数据范围: int

重定向文件读入

优化: 无

cin

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# include <bits/stdc++.h>
using namespace std;
int main() { 
    int n, k;
    cin >> n;
    for(int i = 1; i <= n; i++) { 
        cin >> k;
    }
}
/*
    real    0m8.912s
    user    0m8.844s
    sys     0m0.048s
*/

cin 取消兼容stdio

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# include <bits/stdc++.h>
using namespace std;
int main() { 
    ios::sync_with_stdio(false);
    int n, k;
    cin >> n;
    for(int i = 1; i <= n; i++) { 
        cin >> k;
    }
}
/*
	real	0m1.897s
	user	0m1.844s
	sys		0m0.032s
*/

scanf

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# include <bits/stdc++.h>
using namespace std;
int main() { 
    int n, k;
    scanf("%d", &n);
    for(int i = 1; i <= n; i++) { 
        scanf("%d", &k);
    }
}
/*
    real	0m2.180s
    user	0m2.140s
    sys	    0m0.028s
*/

getchar()

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# include <bits/stdc++.h>
using namespace std;
inline int gn() { 
    int k = 0, f = 1;
    char c = getchar();
    for(; !isdigit(c); c = getchar()) if(c == '-') f = -1;
    for(; isdigit(c); c = getchar()) k = k * 10 + c - '0';
    return k * f;
}
int main() { 
    int n, k;
    n = gn();
    for(int i = 1; i <= n; i++) { 
        k = gn();
    }
}
/*
	real	0m1.642s
	user	0m1.588s
	sys		0m0.052s
*/

fread()

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# include <bits/stdc++.h>
using namespace std;
inline char getc() { 
    static char buf[1 << 18], *fs, *ft;
    return (fs == ft && (ft = (fs = buf) + fread(buf, 1, 1 << 18, stdin)), fs == ft) ? EOF : *fs++;
}
inline int gn() { 
    register int k = 0, f = 1;
    register char c = getc();
    for(; !isdigit(c); c = getc()) if(c == '-') f = -1;
    for(; isdigit(c); c = getc()) k = k * 10 + c - '0';
    return k * f;
}
int main() { 
    int n, k;
    n = gn();
    for(int i = 1; i <= n; i++) { 
        k = gn();
    }
}
/*
	real	0m0.648s
	user	0m0.608s
	sys		0m0.036s
*/

显而易见，在OI系列比赛中，快读保平安233